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21 — Exploiting VBXes

by Brad Shannon

Visual Basic extensions (VBXes) and OLE custom controls (OCXes) are extra or third-party components that can be added to your Visual Basic project. Custom controls provide additional functionality and capabilities to your application. The functionality and capabilities are built into the components. The custom controls can range from text boxes that provide additional capabilities, such as automatic text selection, to complete spreadsheets or word processing applications.

By using custom controls, you are able to greatly reduce the effort that is needed in order to add additional functions and features to your application.

Comparing 16-Bit VBXes to 32-Bit OCXes

VBX custom controls have been available since Version 1.0 of Visual Basic. VBX custom controls currently are supported in other development environments (Microsoft C++ and Delphi, for example). With the release of version 4.0 of Visual Basic, the OCX type of custom control was introduced. The OCX control is based on the OLE version 2 application model. Currently, this type of control is supported by Visual Basic 4.0 and Access 2.0. Other development platforms will be able to host OCX controls (Visual Fox Pro and Microsoft C++ 4.0, for example). OCX controls exist in both 16-bit and 32-bit models, whereas VBX controls exist only in 16-bit models.

The 16-bit version of Visual Basic supports both 16-bit OCX controls and 16-bit VBX controls. The 32-bit version of Visual Basic supports only 32-bit OCX controls.

VBX and OCX Controls

If your application is using custom controls, you must be aware of the following points and potential problems when using OCX/VBX controls. As there are many applications created with Visual Basic, there is a good chance you could find yourself in a situation similar to that described here:

In the next section, you learn how to retrieve the Windows version information based on the name of the file passed to it.

Adding Custom Controls to Your Project

In order to add a custom control to your application, you will need to use the Custom Controls dialog (see Figure 21.1). The contents of the Custom Controls dialog is determined based on the state of the control's insertable objects, selected items only, and check boxes. If you select controls, then all of the OCX and VBX controls that have been registered with the OLE registry will be displayed. If you select Insertable objects, all of the OLE objects that have been registered with the OLE registry will be displayed (an example of an insertable object is an Excel spreadsheet). If the control is part of the current project, an X appears at the left of the control. If a control is installed on your system, but it is not listed in the Available Controls list, you can add it to the list by clicking the Browse button. Selected items will display only the custom controls and insertable objects that are part of the current project. You are unable to remove a control from the selected item that is currently being used in your project.


Figure 21.1. Illustrates the Custom Control Selection dialog.

In order to add a VBX or OCX control to your project, you need to complete the following steps:

  1. Choose Tools | Custom Controls.

  2. Select the control that you wish to add by clicking on the box to the left of the control (for example, the Common Dialog control).

  3. Once the control has been selected, a graphic representation of the control will be visible in your toolbox (see Figure 21.2).

  4. Once the control is part of your toolbox, it can be used in the same manner as any other Visual Basic control.


Figure 21.2. The toolbox with the newly added common Dialog control.

Standard Edition versus Professional Edition Custom Controls

The Standard Edition of Visual Basic contains five custom controls; the Professional Edition of Visual Basic contains 19 custom controls. These controls were obtained from various VBX and OCX vendors who may sell another version of the control with additional functionality. Some of the commercial counterparts to the custom controls covered in this chapter are covered in Chapter 30, "Using Third Party VBX/OCX Controls." Table 21.1 lists the controls included in each version. 

Custom Control


Standard Edition


Professional Edition

3D Controls


X

Animated Button


X

Data Bound ComboBox

X

X

Data Bound Grid

X

X

Data Bound ListBox

X

X

Common Dialog

X

X

Communications


X

Crystal Reports


X

Gauge


X

Graph


X

Grid

X

X

Key State


X

MaskEdit TextBox


X

Microsoft Mail


X

MultiMedia


X

Outline


X

Picture Clipping


X

Spin


X

Tabbed Dialog


X

The 32-bit version of Visual Basic also includes controls that can be used only in Windows 95 and Windows NT 3.51 and later. These additional controls are shown in Table 21.2. 

Control


Function

ImageList

Enables you to store bitmap images that then can be used by the other controls listed in this table

ListView

Provides the Standard view so that you can display the contents of folders

ProgressBar

Adds the new Windows 95 type progress indicator; provides a function similar to the Gauge custom control

RichText

Displays documents in Rich Text format

Slider

Indicates a sliding scale

StatusBar

Adds the new Windows 95 status bar; provides a function similar to the KeyStats custom control

TabStrip

The Tab Strip control can be used as an alternative to tabbed dialog control supplier with the Professional Edition of Visual Basic. Additionally, the TabStrip control can be used in order to provide a group of push buttons where only one button may be depressed at any one time.

Toolbar

Adds the functionality of a toolbar to your application

Distributing Applications that Use Custom Controls

If the project you have developed includes custom controls, the files relating to these custom controls must be included when you distribute your application. The easiest method to ensure that the correct files are distributed is to use the SetupWizard application that is included with Visual Basic. Once you have completed your application, you need to perform the following steps in order to create distribution diskettes.

  1. Start the SetupWizard Application by double-clicking on the SetupWizard icon contained in the Visual Basic Program Group. You will see a dialog like the one illustrated in Figure 21.3.

    Once the SetupWizard has started, you need to supply the path to your applications project file. You can also indicate if you want your project recompiled prior to the creation of your distribution media. The SetupWizard will then read through all of the files in your project in order to determine if there are any external files that need to be included. If you have selected the compile option, the SetupWizard will also recompile your application. Once you have entered your project file name, press the Next button in order to continue to the next step.


    2. Figure 21.3. SetupWizard startup.

  2. Once the SetupWizard has completed step one, you will then be prompted with a list of external Data Access Engines (DBASE III, for example) that may be needed by your application (see Figure 21.4). If your application does not perform any data access or uses the Jet engine exclusively, you may skip this step; otherwise, select the appropriate items from the list. Once you have completed this step, press the Next button in order to continue to the next step.


    3. Figure 21.4. SetupWizard Data Access Engine selection.

    Note

    You can go back a step by pressing the Back button.
  3. Once the SetupWizard has completed step two, you will then be prompted for the destination drive and directory for the distribution files (see Figure 21.5). You are able to place your distribution files either directly on diskette or save them to your PC's hard disk and copy them at a later date. Once you have selected the destination drive and directory, press the Next button in order to continue to the next step.


    4. Figure 21.5. SetupWizard Destination selection.

  4. Once the SetupWizard has completed step three, you will then be prompted to add any needed OLE servers to the distribution files (see Figure 21.6). If your application is using OLE Servers, enter the details via the Add OLE Servers dialog. Once this is complete, press the Next button in order to continue to the next step.

  5. Once the SetupWizard has completed step four, you will be prompted with a list of files that the SetupWizard has determined that need to be distributed with your application (see Figure 21.7). If there are files included in the list that you do not wish to distribute (for example, you know they are resident on the user's Machine), clear the check box next to the file. Once you are satisfied with the files included for distribution, press the Next button in order to continue to the next step.


    6. Figure 21.6. SetupWizard OLE Server setup.


    Figure 21.7. SetupWizard OLE Server setup.

  6. Once the SetupWizard has completed step five, you will be prompted for the type of application that you are distributing (see Figure 21.8). If you are distributing an OLE shared component, the component will be installed in the shared OLE components directory; otherwise, the application will be installed into a directory of the user's choice.

  7. Once the SetupWizard has completed step six, you will be prompted with a final list of files that the SetupWizard has determined should be distributed with your application (see Figure 21.9). You are able to deselect files in the same manner as described in step five. Additionally, you can specify additional files that you may wish to distribute with your application (an example of an additional file would be a database). If you wish to add additional files, select the Add button and enter the path to the files that you wish to add. Once you have finalized the contents of your application, you should save a template that can then be used in future distribution builds by the SetupWizard.

    Once you have completed this step, press the Finish button, and the SetupWizard will compress all of the distribution files and copy them to the destination that was indicated in step three. The SetupWizard will also create a setup program that can be used to install the application.


Figure 21.8. SetupWizard OLE Server setup.


Figure 21.9. SetupWizard Files Addition, removal.

Using the Professional Edition Controls

The following sections discuss the main purposes of the controls and provide examples to illustrate the behaviors of these controls.

Note

The Crystal Reports Custom Control is covered in Chapter 8, "Reporting Mechanisms."

3D Controls

Six controls are included with the 3D controls:

The 3D controls are similar to existing Visual Basic controls (the check box, for example). However, the 3D controls contain additional properties. Some of the enhancements over the standard Visual Basic controls follow:

To check out some of the capabilities of some of the 3D controls, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section in order to add the Sheridan 3D controls to your project.

  3. Double-click on the Picture control (PictureBox in ToolTips display) contained in the toolbox in order to place a Picture control on your form.

  4. Include the following property settings for the Picture control:

    Align = Align Top
    Appearance = 1-Flat
    BackColor = Grey
    Left = 0
    Height = 465
    Width = 6690

  5. Single-click the 3D Ribbon control contained in the toolbox (SSRibbon in ToolTips display). Draw three 3D Ribbon controls on to the picture control.

  6. Include the following property settings for the 3D Ribbon button control:

    SSRibbon1

    Autosize = 2 - Autosize button to Picture
    Name = ribBold
    GroupNumber = 1
    Left = 4260
    PictureDisabled= c:\vb40\bitmaps\toolbar3\bld-dis.bmp
    PictureDn= c:\vb40\bitmaps\toolbar3\bld-mds.bmp
    Pictureup= c:\vb40\bitmaps\toolbar3\bld-up.bmp

    SSRibbon2

    Autosize = 2 - Autosize button to Picture
    Name = ribCenter
    GroupNumber = 2
    Left = 4800
    PictureDisabled= c:\vb40\bitmaps\toolbar3\cnt-dis.bmp
    PictureDn= c:\vb40\bitmaps\toolbar3\cnt-mds.bmp
    Pictureup= c:\vb40\bitmaps\toolbar3\cnt-up.bmp

    SSRibbon3

    Autosize = 2 - Autosize button to Picture
    Name = ribItalic
    GroupNumber = 3
    Left = 5280
    PictureDisabled= c:\vb40\bitmaps\toolbar3\itl-dis.bmp
    PictureDn= c:\vb40\bitmaps\toolbar3\itl-mds.bmp
    Pictureup= c:\vb40\bitmaps\toolbar3\itl-up.bmp

  7. Single-click the 3D Command Button control contained in the toolbox (SSCommand in ToolTips display). Draw one 3D Command Button control on the Picture control.

  8. Include the following property settings for the 3D Command button control:

    Autosize = 2 - Autosize button to Picture
    Name = cmdHelp
    Left = 5880
    Picture= c:\vb40\bitmaps\toolbar3\hlp-up.bmp

  9. Add the following code to the cmdHelp_Click event.

    MsgBox " Help Button Was Pressed "

  10. Double-click on the 3D Panel control (SSPanel in ToolTips display) contained in the toolbox in order to place a 3D Panel on to your form.

  11. Include the following property settings for the 3D Panel control:

    BevelInner = 1- Insert Bevel
    BevelOuter = 2- Raised Bevel
    BevelWidth = 1
    BorderWidth =1
    Caption =
    FloodShowPCt = True
    FloodType = 1 - From Left to Right
    Height = 315
    Left = 1800
    Name = pnlGauge
    Top = 5520
    Width = 6690

  12. Double-click on the 3D Command Button control (SSCommand in ToolTips display) contained in the toolbox in order to place a 3D Command Button on your form.

  13. Include the following property settings for the 3D Command button control:

    Caption = &Gauge
    Height = 495
    Left = 1920
    Name = cmdGauge
    Top = 3300
    Width = 1215

  14. Add the following code to the cmdGauge_Click event:

    Dim x As Integer
    Dim y As Integer
    Screen.MousePointer = 11
    ' Gauge in Panel
    For x = 1 To 100

    pnlgauge.FloodPercent = x
    If x = 49 Then

    pnlgauge.ForeColor = &HFFFFFF

    End If

    For y = 1 To 1000

    DoEvents

    Next y

    Next x

    Screen.MousePointer = 0

  15. Press the F5 key to run the project.

Once the project is running, you can click the Gauge button; the pnlGauge control displays a progress bar (see Figure 21.10). Clicking the Help command button displays a message box indicating that the button has been pressed. You can also see the behavior of non-grouped Ribbon buttons.


Figure 21.10. Illustrates the use of the 3D Panel Control as a progress meter.

Animated Button

You use the Animated Button control to show a series of pictures to emulate animation. If you want to determine the bitmap that is displayed or to change the currently displayed bitmap, you should retrieve or change the Value property. You can use this control to convey a series of images to the user, much like a cartoon.

In the example in this section, you use the Animated Button control to step through the four suites available in a deck of cards. All the pictures used in this example are located in the Assorted bitmaps directory.

To use the Animated Button control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Desaware Animated Button control to your project.

  3. Double-click on the Animated Button control (AniPushButton in ToolTips display) contained in the toolbox in order to place an Animated Button on your form.

  4. Press the F4 key in order to access the property setting of the newly added Animate button. Select the Custom property. You will then be presented with a Tabbed dialog displaying the Custom properties that can be changed. Enter the following property settings:

    General Tab 1

    Cycle - 1- By Frame
    BorderStyle - None
    PictdrawMode - Autosize

    General Tab 2

    Caption - Empty String
    Speed - 32767
    Value - 1

    Frame Setting Tab

    Select Frame 1
    Load file c:\vb40\bitmaps\assorted\club.bmp

    Select Frame 2
    Load file c:\vb40\bitmaps\assorted\diamond.bmp

    Select Frame 3
    Load file c:\vb40\bitmaps\assorted\heart.bmp


    Select frame 4
    Load file c:\vb40\bitmaps\assorted\spade.bmp

    5. NOTE

    The Bitmaps\Assorted directory is located inside the directory in which Visual Basic was installed.
  5. After all of the above property settings have been completed, press the OK button.

  6. Enter the following code in the AniPushButton1_Click event:

    AniPushButton1.Value = 1

    For x = 1 To 10000
    DoEvents
    Next

    AniPushButton1.Value = 2

    For x = 1 To 10000
    DoEvents
    Next

    AniPushButton1.Value = 3

    For x = 1 To 10000
    DoEvents
    Next

    AniPushButton1.Value = 4

  7. Press the F5 key to run the project.

  8. Click the AniButton control so that your application will cycle through the four bitmaps.

Because the displayed bitmaps are fairly small and do not take much time to load, DoEvents loops are needed. Otherwise, the pictures would change so quickly that you would be unable to see them. If the picture flips too slowly, decrease the counter value for the loops; if the bitmaps change too quickly, you might want to increase the delay. In order to increase or decrease the delay, alter the value of the To parameter in the For statements contained in the AniPushButton1_Click event.

Data Bound ComboBox

You can use the Data Bound ComboBox control to display the information stored in a database in a combo box without having to manually add the items, as you would if you were using an unbound combo box. You can update the contents of different fields based on the selection made in the combo box.

Suppose that you have a master record containing a code-type field (PubID), and its definition is defined in another table (Publishers). When the description of the code field (Publishers) is selected from the ListBox, the equivalent code (PubID) is updated in the master record.

The following example illustrates a combo box bound to the Publishers table. When a selection is made, the PubID field in the Titles table is updated. Follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Data Bound List controls to your project.

  3. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your form.

  4. Include the following property settings for the Data control:

    DatabaseName = C:\vb40\biblio.mdb
    Recordsource = select * from titles

  5. Double-click on the Data Control (Data in ToolTips display) contained in the toolbox to place a Data control on your form.

  6. Include the following property settings for the Data Bound List control:

    name = dtaList
    DatabaseName = C:\vb40\biblio.mdb
    Height = 1815
    Left = 3780
    Top = 1260
    Width = 2895
    Recordsource = select * from publishers

  7. Double-click on the Data Bound ComboBox control (DBCombo in ToolTips display) contained in the toolbox to place a Data Bound ComboBox control on your form.

  8. Include the following property settings for the Data Bound ComboBox control:

    BoundColumn = PUBID
    DataField = PUBID
    DataControl = Data1
    Height = 315
    Left = 1560
    ListField = name
    Name = dbCompub
    RowSource = dtaList
    Top = 180
    Width = 3135

  9. Double-click on the TextBox control (TextBox in ToolTips display) contained in the toolbox in order to place a TextBox control on to your form.

  10. Include the following property setting for the TextBox control:

    Height = 315
    Left = 1680
    Name = txtPubid
    Top = 1260
    Width = 675

  11. Double-click on the Label control (Label in ToolTips Display) contained in the toolbox to place a Label control on your form.

  12. Include the following property setting for the Label control:

    Caption = Publisher
    Height = 195
    Left = 120
    Name = pnlTitle
    Top = 240
    Width = 1215

  13. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your form.

  14. Include the following property setting for the Label control:

    Caption = Publisher ID
    Height = 195
    Left = 120
    Name = pnlPubid
    Top = 1320
    Width = 1215

  15. Add the following code to the dbcompub_Click event:

    txtPubid.Text = dbCompub.BoundText

  16. Press the F5 key in order to run the project.

The combo box contains the publisher's name. When the publisher's name is selected from the combo box, the PubID field is displayed in the text box (see Figure 21.11).


Figure 21.11. The Data Bound combo box.

Data Bound Grid

You can use the Data Bound Grid to enable your application to display the recordset of a data control in row/column format. The contents of the recordset can be a complete table or the results of an SQL statement. You can perform the following functions on data displayed in the grid:

You can set the contents of each column of the grid by specifying the field the column will hold. The caption for the column defaults to the name of the database field. You can change this caption to something more descriptive at design time and runtime. At runtime and design time, you can determine which features will be available to the users of your application, and you can limit the action that will be permitted on the recordset.

To understand the capabilities of the Data Bound Grid control, follow these steps:

  1. Use the File | New Project command to open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Apex Data Bound Grid control to your project.

  3. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your form.

  4. Double-click on the Data Bound Grid control (DBGrid in ToolTips display) contained in the toolbox to place a Data Bound Grid control on your form.

  5. Click and drag the top-left corner of the Data Bound Grid control to the top-left corner of the form. Click and drag the bottom-right corner of the Data Bound Grid so that the Data Bound Grid occupies most of your form.

  6. Include the following property settings in the Data control:

    DatabaseName = C:\vb40\biblio.mdb
    Recordsource = select * from titles order by title

  7. Include the following property setting for the Data Bound Grid control:

    DataSource = Data1

  8. Press the F5 key to run the project.

When the project is running, you should see the contents of the Titles table from the BIBLIO database, in order by book title (see Figure 21.12). You can edit the records contained in the grid. Select a complete row for deletion. Add new records to the table. Resize the columns and rows. Then scroll through the complete table.


Figure 21.12. Using the Data Bound Grid control.

Data Bound ListBox

You can use the Data Bound ListBox control to display the information stored in a database in a ListBox without having to manually add the items, as you would if you were using an unbound ListBox. You can update the contents of different fields based on the selection made in the ListBox.

Suppose that you have a master record containing a code-type field (PubID), and its definition is provided in another table (Publishers). When the description of the code field (Publishers) is selected from the ListBox, the equivalent code (PubID) is updated automatically in the master record.

The following example illustrates a ListBox that is bound to the Publishers table. When a selection is made, the Publisher's ID is updated to the Titles table. Follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Data Bound List controls to your project.

  3. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your form.

  4. Include the following property settings for the Data control:

    DatabaseName = C:\vb40\biblio.mdb
    Recordsource = select * from titles order by title

  5. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your form.

  6. Include the following property settings for the Data control:

    name = dtaList
    DatabaseName = C:\vb40\biblio.mdb
    Height=1875
    Left=3780
    Top=1260
    Width=2895
    Recordsource = select name,pubid,pubid & " " & name as test from publishers

  7. Double-click on the Data Bound ListBox (DBList in ToolTips display) contained in the toolbox to place a Data Bound ListBox control on your form.

  8. Include the following property settings for the Data Bound ListBox control:

    BoundColumn = PUBID
    DataField = PUBID
    DataControl = Data1
    Height=1815
    Left=3780
    Listfield = test
    Name = dblistPub
    RowSource = dtaList
    Top=1260
    Width=2895

  9. Double-click on the TextBox (Text in ToolTips display) contained in the toolbox to place a TextBox control on your form.

  10. Include the following property setting for the TextBox control:

    Height = 315
    Left = 1680
    Name = txtPubid
    Top = 1260
    Width = 675

  11. Add the following code to the dbListpub_Click event:

    txtPubid.Text = dblistPub.BoundText

  12. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your form.

  13. Include the following property setting for the Label control:

    Caption = Publisher
    Height = 195
    Left = 120
    Name = pnlTitle
    Top = 240
    Width = 1215

  14. Press the F5 key to run the project.

The contents of the ListBox will be a combination of the publisher's ID and the publisher's name. When an entry is selected, the PubID field in the Titles table is updated based on the PubID of the selection made. The publisher ID is also displayed in the List Box.

The Common Dialog

You can use the Common Dialog control to enable your application to display dialog boxes consistent with those of other Windows applications. You use the Common Dialog control to prompt users to perform certain actions. The user interface elements provided by this control follow: 

Element


Function

Color

Prompts the user to select or define a color.

File Open

Prompts the user to select the location and the file to open.

File Save

Prompts the user to save a file, specifying the name and location of the file being saved.

Fonts

Prompts the user to select a font.

Printer

Prompts the user to select or change the active printer or to change the printer's characteristics. An example of this would be the tray to be used for printing or the paper to be used.

WinHelp

Enables the user to evoke the WinHelp program to open a specified Windows Help file at a certain location.

NOTE

You cannot set the location in which a Common Dialog will be displayed on the screen.

To use the Common Dialog control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Common Dialog control to your project.

  3. Double-click on the Command Button control (CommandButton in ToolTips Display) contained in the ToolBox and place five command buttons on your form.

  4. Using the property editor, set the following properties of the command buttons:

    Command Button 1

    Left = 120
    Name = cmdColor
    Top = 4260
    Width = 1215

    Command Button 2

    Left = 2760
    Name = cmdFonts
    Top = 3660
    Width = 1215

    Command Button 3

    Left = 5400
    Name = cmdHelp
    Top = 3660
    Width = 1215

    Command Button 4

    Left = 120
    Name = cmdOpen
    Top = 3660
    Width = 1215

    Command Button 5

    Left = 4080
    Name = cmdPrint
    Top = 3660
    Width = 1215

    Command Button 6

    Left = 1440
    Name = cmdSave
    Top = 3660
    Width = 1215

  5. Double-click on the Common Dialog control (Common Dialog in ToolTips display) contained in the toolbox to place a Label control on your form.

  6. In order to illustrate some of the functionality of the Color Common dialog, enter the following code in the cmdColor_Click event:

    CommonDialog1.DialogTitle = " Select A Color "
    CommonDialog1.Flags = &H2
    CommonDialog1.ShowColor
    MsgBox " The following Color has Been Selected " & CommonDialog1.Color
    the flag property indicates that the user will be able to define custom colors.

  7. In order to illustrate some of the functionality of the Fonts Common dialog, enter the following code in the cmdFonts_Click event:

    CommonDialog1.DialogTitle = " Select A Font "
    CommonDialog1.Flags = &H40000
    CommonDialog1.ShowFont
    the flag property indicates that only TrueType fonts will be displayed

  8. In order to illustrate some of the functionality of the Help Common dialog, enter the following code in the cmdHelp_Click event:

    CommonDialog1.DialogTitle = " Select A Help Topic "
    CommonDialog1.HelpCommand = &H4
    CommonDialog1.ShowHelp
    the flag property indicates that the Help on Help Function will be run

  9. In order to illustrate some of the functionality of the File Open Common dialog, enter the following code in the cmdOpen_Click event:

    CommonDialog1.DialogTitle = " Open A File "
    CommonDialog1.Filter = "*.*"
    CommonDialog1.FileName = "*.*"
    CommonDialog1.ShowOpen
    MsgBox " You have selected " & CommonDialog1.FileName & " As the file to Open"

  10. In order to illustrate some of the functionality of the Print Common dialog, enter the following code in the cmdPrint_Click event:

    CommonDialog1.DialogTitle = " Select A Printer "
    CommonDialog1.Flags = &H100&
    CommonDialog1.ShowPrinter
    the flag property indicates to return the printer HDC once it has been selected
    MsgBox " The Selected printer has the Windows device handle of " & CommonDialog1.hDC

  11. In order to illustrate some of the functionality of the Save as Common dialog, enter the following code in the cmdSave_Click event:

    CommonDialog1.DialogTitle = " Save A File "
    CommonDialog1.Filter = "*.*"
    CommonDialog1.FileName = "*.*"
    CommonDialog1.Flags = &H2&
    CommonDialog1.ShowSave
    MsgBox " You have selected " & CommonDialog1.FileName & " As the file to Save to "the flag property indicates the user will be prompted if an existing file has been selected

  12. Press the F5 key to run the project.

When the project is running, you are able to see the behavior of all the available common dialog boxes. When you open or save a file, a message box appears indicating the name of the file selected (see Figure 21.13). When a color is selected from the colors Common Dialog box, the Windows internal representation of the color will be displayed in a message box. The Help dialog box takes the user to Windows Help. When a Printer is selected from the printers Common Dialog box, the Windows device context ID for that printer will be displayed in a message box. The Font dialog box tells the user which font is selected.


Figure 21.13. The Save As File dialog box.

Communications

You can use the Communications control to enable your application to communicate through the serial ports of the computer on which it is running. You must use one control for each serial port that you want to control. You are able to control the following aspects of the device (modem) attached to the serial port of your computer where your application is running:

The Communications control can be used to develop applications as simple as telephone dialer or as complicated as a complete communications package.

The following example illustrates the use of the Communications control to dial a telephone number. Follow these steps:

  1. Use the File | New Project command to open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Comm control to your project.

  3. Double-click on the Communication control (MSComm in ToolTips display) contained in the toolbox to place a Label control on your form.

  4. Double-click on the Command Button (CommandButton in ToolTips display) contained in the toolbox to place a Command Button control on your form.

  5. Include the following property setting for the Command Button control:

    Name = cmdHangUp
    Caption = "&Hang Up"
    Height = 395
    Left = 4380
    Top = 3480
    Width = 1215

  6. Double-click on the Command Button (CommandButton in ToolTips display) contained in the toolbox to place a Command Button control onto your form.

  7. Include the following property setting for the Command Button control:

    Name = cmdDial
    Caption = "&Dial"
    Height = 395
    Left = 2940
    Top = 3480
    Width = 1215

  8. Double-click on the ComboBox control(ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  9. Include the following property setting for the ComboBox control:

    Name = comParity
    Height = 315
    Left = 3000
    Style = 2 'Dropdown List
    Top = 2880
    Width = 1755

  10. Double-click on the ComboBox control(ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  11. Include the following property setting for the ComboBox control:

    Name = comStopBits
    Height = 315
    Left = 3000
    Style = 2 'Dropdown List
    Top = 2400
    Width = 1755

  12. Double-click on the ComboBox control(ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  13. Include the following property setting for the ComboBox control:

    Name = comDataBits
    Height = 315
    Left = 3000
    Style = 2 'Dropdown List
    Top = 1920
    Width = 1755

  14. Double-click on the ComboBox control (ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  15. Include the following property setting for the ComboBox control:

    Name = comLineSpeed
    Height = 315
    Left = 3000
    Style = 2 'Dropdown List
    Top = 1440
    Width = 1755

  16. Double-click on the ComboBox control (ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  17. Include the following property setting for the ComboBox control:

    Name = comCommPort
    Height = 315
    Left = 3000
    Style = 2 'Dropdown List
    Top = 960
    Width = 1755

  18. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  19. Include the following property setting for the Label control:

    Name = txtNumber
    Height = 300
    Left = 3000
    Top = 480
    Width = 2355

  20. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  21. Include the following property setting for the Label control:

    Name = lblParity
    Caption = "Parity"
    Height = 300
    Left = 420
    Top = 2880
    Width = 2175

  22. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  23. Include the following property setting for the Label control:

    Name = lblStopBits
    Caption = "Stop Bits"
    Height = 300
    Left = 420
    Top = 2400
    Width = 2175

  24. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  25. Include the following property setting for the Label control:

    Name = lblDataBits
    Caption = "Data Bits"
    Height = 300
    Left = 420
    Top = 1920
    Width = 2175

  26. Double-click on the Label control (Label in ToolTips Display) contained in the toolbox to place a Label Control on your form.

  27. Include the following property setting for the Label control:

    Name = lbl_linespeed
    Caption = "Line Speed"
    Height = 300
    Left = 420
    Top = 1440
    Width = 2175

  28. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  29. Include the following property setting for the Label control:

    Name = lblCommPort
    Caption = "Communication Port"
    Height = 300
    Left = 420
    Top = 960
    = 2175

  30. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label Control on your form.

  31. Include the following property setting for the Label control:

    Name = lblNumber
    Caption = "Number To Dial"
    Height = 295
    Left = 420
    Top = 480
    Width = 2175

  32. Add the following code to the Form_Load event:

    comCommPort.AddItem "Com1:"
    comCommPort.AddItem "Com2:"
    comCommPort.AddItem "Com3:"
    comCommPort.AddItem "Com4:"

    comDataBits.AddItem "8"
    comDataBits.AddItem "7"
    comLineSpeed.AddItem "19200"
    comLineSpeed.AddItem "14400"
    comLineSpeed.AddItem "9600"
    comLineSpeed.AddItem "4800"
    comLineSpeed.AddItem "2400"
    comLineSpeed.AddItem "1200"

    comParity.AddItem "N- None"
    comParity.AddItem "O - Odd"
    comParity.AddItem "E - Even"
    comParity.AddItem "E - Mark"
    comParity.AddItem "S - Space"

    comStopBits.AddItem "1"
    comStopBits.AddItem "1.5"
    comStopBits.AddItem "2"

  33. Add the following code to the comCommPort_Click event:

    Select Case comCommPort.TEXT

    Case "Com1:"

    MSComm1.CommPort = 1

    Case "Com2:"

    MSComm1.CommPort = 2

    Case "Com3:"

    MSComm1.CommPort = 3

    Case "Com4:"

    MSComm1.CommPort = 4

    End Select

  34. Add the following code to the cmdDial_Click event:

    If Len(comCommPort.TEXT) = 0 Then

    MsgBox " You must Select a Communications Port prior to Dialing"
    Exit Sub

    End If

    If Len(txtNumber.TEXT) = 0 Then

    MsgBox " You Have Not Entered a Number Dial "
    Exit Sub

    End If

    MSComm1.Settings = comLineSpeed.TEXT & "," & Mid$(comParity.TEXT, 1, 1) & "," & comDataBits.TEXT & "," & comStopBits.TEXT
    MSComm1.PortOpen = True
    MSComm1.Output = "ATDT" & "9," & txtNumber.TEXT & Chr$(13) ' Dial the requested number

  35. Add the following code to the cmdHangUp_Click event:

    MSComm1.Output = "ATH0" + Chr$(13)
    MSComm1.PortOpen = False

  36. Press the F5 key to run the project.

Once the project is running, you can select the Com: port that the modem is attached to. Additionally, you can set the communication protocol that the modem will employ (this will have no effect on the example; it is only included for illustration). If you enter the telephone number that you want to dial in to the TextBox and press the Enter key, the number will be dialed for you. In order to disconnect the modem, press the Hang Up button.

Gauge

You use the Gauge control to indicate the progression or status of a process. The gauge can be a horizontal or vertical bar that fills as the process takes place, or it can be a needle-type indication, much like that of a speedometer. You control the position of the gauge's progress by the Value property. If the Value property exceeds the Gauge control's Maximum property, the value is reset to the value of the Maximum property. If the Value property is less than the Minimum property value, the Value property is reset to the value of the Minimum property.

To learn how to use the Gauge control, go through the steps in the following procedure to create a gauge to indicate progress via a clock-like indicator. The picture used in this example is located in the Gauge directory. Follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microhelp Gauge control to your project.

  3. Double-click on the Gauge control (Gauge in ToolTips display) contained in the toolbox to place a Gauge on your form.

  4. Press the F4 key to access the property setting of the newly added Gauge. Select the Custom Property. You will be presented with a Tabbed dialog displaying the custom properties that can be changed. Enter the following property settings:

    General Tab 1

    InnerTop = 20
    InnerBottom = 20
    InnerLeft = 20
    InnerRight = 20
    Max = 100
    Min = 0
    NeedleWidth = 2
    Style = 3 Full Needle

    Pictures Tab
    Select the Picture Property and select the circclock.bmp.

  5. Using your mouse, click and drag the lower-right edge of the Gauge control so that you are able to fully view the clock bitmap.

  6. Double-click on the Command Button control (CommandButton in ToolTips display) contained in the toolbox to place a Command Button control on your form.

  7. Enter the following code in the command1_Click event:

    Dim x As Integer
    Dim y As Integer

    Screen.MousePointer = 0

    For x = 1 To 100

    Gauge1.Value = x

    For y = 1 To 1000

    DoEvents

    Next y

    Next x

    Screen.MousePointer = 0

  8. Press the F5 key to run the project.

Click the Command button. The needle on the graph moves around the clock (see Figure 21.14), indicating the progress of your operation. You might want to add a text panel to indicate the percentage of completion.


Figure 21.14. The Gauge control.

Graph

You can use the Graph control to quickly present numerical information graphically. The Graph control provides the following types of pre-built graphs:

When designing your application, you can preview the types of graphs by setting the RandomData property to On. After you create a graph in your application, you can print it or copy it to the Clipboard for use in another application. Because the Graph control uses a graphical drawing engine in addition to the VBX or OCX control, all changes to the data used by the graph are reflected in the graph almost immediately.

The following example will illustrate the different types of graphs that can be created using the Graph control. The Data used for the graph is provided using the QuickData property of the Graph control. To create the sample application using the Graph control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Pinnacle-BPS Graph control to your project.

  3. Double-click on the Graph control (Graph in ToolTips Display) contained in the toolbox to place a Graph control on your form.

  4. Include the following property setting for the Graph control:

    Name = Graph1
    Height = 4215
    Left = 60
    Top = 0
    Width = 6615
    BorderStyle = 1
    RandomData = 0
    ColorData = 0

  5. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your form.

  6. Include the following property setting for the Label control:

    Name = lblGraph
    Caption = "Graph Type"
    Height = 375
    Left = 240
    Top = 4680
    Width = 1215

  7. Double-click on the ComboBox control (ComboBox in ToolTips display) contained in the toolbox to place a ComboBox control on your form.

  8. Include the following property setting for the ComboBox control:

    Name= comGraph
    Height = 315
    Left = 2100
    Style = 2 'Dropdown List
    Top = 4680
    Width = 4275

  9. Enter the following code in the Form_Load event:

    Dim sTAB As String
    Dim sCRLF As String
    Dim sTestData As String
    sTAB = Chr$(9)
    sCRLF = Chr$(13) + Chr$(10)
    sTestData = "11" & sTAB & "12" & sTAB & "13" & sCRLF & "5" & sTAB & "6" & sTAB_ & "7" + sCRLF & "20" & sTAB & "21" & sTAB & "22" & sCRLF
    Graph1.QuickData = sTestData

    Graph1.LegendText = " HardWare"
    Graph1.LegendText = " SoftWare"
    Graph1.LegendText = " Services "
    Graph1.LabelText = "USA"
    Graph1.LabelText = "Europe"
    Graph1.LabelText = "Asia"

    comGraph.AddItem "1 - 2D Pie"
    comGraph.AddItem "2 - 3D Pie"
    comGraph.AddItem "3 - 2D Bar"
    comGraph.AddItem "4 - 3D Bar"
    comGraph.AddItem "5 - Gantt"
    comGraph.AddItem "6 - Line"
    comGraph.AddItem "7 - Log/Lin"
    comGraph.AddItem "8 - Area"
    comGraph.AddItem "9 - Scatter"
    comGraph.AddItem "10 - Polar"
    comGraph.AddItem "11 - HlC"
    comGraph.ListIndex = 3

  10. Enter the following code in the comGraph_Click event:

    Graph1.GraphType = CInt(Mid$(comGraph.TEXT, 1, 2))
    Graph1.DrawMode = 2 ' Force the Graph to Re-Draw

  11. Depress the F5 key to run the project.

When the project is running, you will see the data presented as a 3D Bar Graph, as shown in Figure 21.15. You can change the type of graph by selecting a different format from the ComboBox.


Figure 21.15. Using the Graph control.

Grid

You can use the Grid control to display data in a row-and-column format. Unlike the Data Bound Grid control, the Grid control requires that you add data to control using the AddItem method. All editing of the data contained in the grid must be handled by the application. You can place both text and pictures in the cells of the grid. Once the application is running, the user can scroll through the data, resize rows and columns, and select multiple rows of data on which actions supported by your application can be performed.

The following example shows you how to load a grid from the data stored in the Titles table of the BIBLIO database. To use the Grid control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Grid Gauge control to your project.

  3. Double-click on the Grid control (Grid in ToolTips Display) contained in the toolbox to place a Command Button control on your form.

  4. Click and drag the top-left corner of the Grid control to the top-left corner of the form. Click and drag the bottom-right corner of the Grid so that the Grid occupies most of your form.

  5. Include the following property setting for the Grid control:

    Cols= 3

  6. Enter the following code in the Form_Load event:

    Dim ws As WorkSpace
    Dim db As Database
    Dim rs As Recordset

    Screen.MousePointer = 11

    Set ws = DBEngine.CreateWorkspace("ws1", "ADMIN", "")
    Set db = ws.OpenDatabase("C:\vb40\biblio.mdb", False, False)
    Set rs = db.OpenRecordset("select * from Titles order by title", dbOpenDynaset)

    rs.MoveLast
    Grid1.Rows = rs.RecordCount + 2
    rs.MoveFirst

    Grid1.Row = 0

    Grid1.Col = 0
    Grid1.Text = "PUBID"
    Grid1.ColWidth(0) = 1000

    Grid1.Col = 1
    Grid1.Text = "Year"
    Grid1.ColWidth(1) = 1000

    Grid1.Col = 2
    Grid1.Text = "Title"
    Grid1.ColWidth(2) = 3000

    Grid1.Row = 1
    Do While rs.EOF = False

    Grid1.Col = 0

    If Not IsNull(rs("pubid")) Then

    Grid1.Text = rs("pubid")

    End If

    Grid1.Col = 1

    If Not IsNull(rs("year published")) Then

    Grid1.Text CStr(rs("year published"))

    End If

    Grid1.Col = 2

    If Not IsNull(rs("title")) Then

    Grid1.Text = rs("title")

    End If

    rs.MoveNext
    Grid1.Row = Grid1.Row + 1

    Loop

    Screen.MousePointer = 0

  7. Press the F5 key to run the project.

When the project is running, you can see some of the data contained in the Titles table of the BIBLIO database, as shown in Figure 21.16. You can resize the rows and columns of the grid.


Figure 21.16. Using the Grid control.

Key Status

The Key Status control enables you to monitor the status of these keys: Caps Lock, Scroll Lock, Num Lock, and Insert. The status of these keys generally is displayed in an application to give the user a quick reference to each key's status. Generally, the status is displayed at the bottom of an MDI form.

To see how the Key Status control works, create a status bar that displays the status of certain keys at the bottom of an MDI form. Follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microhelp Key State control to your project.

  3. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Sheridan 3D controls to your project.

  4. Using the Insert | MDI Form command, add an MDI form to your project.

  5. Double-click on the Picture control (Picture in ToolTips Display) contained in the toolbox to place a Picture control on your form.

  6. Select the Align property of the Picture control and set it to align Bottom.

  7. Double-click on the Key Status control (MhState in ToolTips display) contained in the toolbox to place four Key Status controls on your form.

  8. Include the following property settings for the Key Status controls:

    Key Status 1

    Name - Keyins
    Style - 2- Insert Key

    Key Status 2

    Name - Keycaps
    Style - 0- Caps Lock

    Key Status 3

    Name - Keynum
    Style - 1- Num Lock

    Key Status 4

    Name - KeyScroll
    Style - 3 - Scroll Lock

  9. Select the 3D panel control (SSPanel in ToolTips display) from the toolbox and draw four panels on the Picture control.

  10. Include the following property settings for the 3D Panel controls:

    3D Panel 1

    Name - pnlins
    BevelInner - 0-No Bevel
    BevelOuter - 1-Inset Bevel
    BevelWidth - 2
    BorderWidth - 2
    Top - 60
    Left - 6060
    Height - 315
    Width - 555

    3D Panel 2

    Name - pnlcaps
    BevelInner - 0-No Bevel
    BevelOuter - 1-Inset Bevel
    BevelWidth - 2
    BorderWidth - 2
    Top - 60
    Left - 3960
    Height - 315
    Width - 555

    3D Panel 3

    Name - pnlnum
    BevelInner - 0-No Bevel
    BevelOuter - 1-Inset Bevel
    BevelWidth - 2
    BorderWidth - 2
    Top - 60
    Left - 4620
    Height - 315
    Width - 555

    3D Panel 4

    Name - pnlscrl
    BevelInner - 0-No Bevel
    BevelOuter - 1-Inset Bevel
    BevelWidth - 2
    BorderWidth - 2
    Top - 60
    Left - 5340
    Height - 315
    Width - 555

  11. Select the Timer control from the toolbox (Timer in ToolTips display) from the toolbox and draw a timer on the Picture control.

  12. Include the following property setting for the Timer control:

    Interval = 1000

  13. Enter the following code in the Timer1_Timer event:

    ' Caps Lock Key

    If keycaps.Value = True Then

    pnlcaps.Caption = "Cap"

    Else

    pnlcaps.Caption = ""

    End If

    ' Num Lock Key

    If keynum.Value = True Then

    pnlnum.Caption = "Num"

    Else

    pnlnum.Caption = ""

    End If

    ' Scroll Lock

    If keyscrl.Value = True Then

    pnlscrl.Caption = "Scrl"

    Else

    pnlscrl.Caption = ""

    End If

    ' Insert Key

    If keyinsert.Value = True Then

    pnlins.Caption = "Ins"

    Else

    pnlins.Caption = "Ovr"

    End If

  14. Press the F5 key in order to run the project.

While your project runs, the current status of the Caps Lock, Scroll Lock, Num Lock, and Insert keys is displayed at the bottom of the MDI form (see Figure 21.17). If these keys are enabled, you see Cap, Num, Scrl, and Ins in the status line. If the keys are not enabled, the keys box in the status line appears blank. When the status of one of these keys changes, the display is updated accordingly.


Figure 21.17. Using the Key Status control.

MaskEdit TextBox

The MaskEdit TextBox control provides the same basic functionality as that of the TextBox control included with Visual Basic. Properties have been added, however, to format the data displayed in the text box. The MaskEdit TextBox control also provides additional properties to indicate the behavior of text stored in the control when it is copied from the text box.

To define a MaskEdit TextBox control in order to display date-related information, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft MaskEdit TextBox control to your project.

  3. Double-click on the MaskEdit TextBox control (MaskEdBox in ToolTips display) contained in the toolbox to place a MaskEdit TextBox control on your form.

  4. Select the Custom Control property of the MaskEdit TextBox control and indicate the following property settings:

    Name = txtDave
    Format = MMMM-DD-YYYY
    name= txtDate
    Width 2200

  5. Add the following code to the Form_Load event:

    txtDate.Text = Now

  6. Press the F5 key to run the project.

As illustrated in Figure 21.18, the MaskEdit TextBox control now contains the current date in the format MMMM-DD-YYYY. Once you have finished this example, save your project because we will be building on it in order to illustrate another custom control.


Figure 21.18. Using the MaskEdit TextBox control.

Microsoft Mail

You must use two controls to create a mail-enabled application: MAPIsession and MAPImessage.

NOTE

For a more in-depth look at a mail-enabled application, see Chapter 25, which concentrates on the Mail API.
NOTE

You must have access to Microsoft Mail and a Microsoft Mail server in order to use the MAPIsession and MAPImessage controls.

You use the MAPIsession control to establish a session between your application and the Microsoft Mail server. No events are associated with the MAPIsession control. All interaction between the control and the Mail server takes place through the methods of the control. Two methods are applicable to the MAPIsession control: Signon (Establish a Session) and Signoff (End a Session). These two methods are used to manage the mail session.

Listing 21.1 illustrates establishing a session and signing off from the session using the MAPIsession control. 

MAPISession1.Username= "MAIL1"

MAPISession1.Password= "Password"

MAPISession1.LogonUI= False   'suppress the Logon Dialog

MAPISession1.Newsession= True   'Establish a new session

MAPISession1.downloadmail= true   'Download all mail when signed on

MAPISession1.signon  'sign on to the Mail server

'Perform Mail-related tasks

MAPISession1.signoff  sign off the Mail server

The MAPImessage custom control enables users to manipulate their messages (using Add, Edit, and Delete) and the Address Book. You can manipulate messages only after a MAPIsession has been established through the MAPIsession custom control. No events are associated with the MAPImessage control; all interaction between the control and the Mail server takes place through the messages and properties of the control.

The following methods are available in the MAPImessage control: 

Method


Function

Compose

Prepares a new message

Copy

Copies an existing message to a new message

Delete

Deletes an existing message

Fetch

Retrieves an existing message for viewing

Forward

Forwards an existing message to another Mail user

Reply

Creates a new message and addresses it to the location of the message to which it is replying

ReplyAll

Creates an empty message addressed to the person and all other users copied on the originating message

ResolveName

Performs a check on all addressees of the message to ensure that they are valid addresses

Save

Saves the current message

Send

Sends a copy of the current message to all addressees

Show

Displays the Address Book

Listing 21.2 shows the steps you should follow to generate a message. 

MAPIMessages1.compose  'Prompt the user to generate a new message

 'User enters address and destination of the Message

MAPIMessage.ResolveName  'Check all Address are Valid

if ERR <> 0 then

     MsgBox "Address ERROR"

end if

MAPIMessage.send(false)  'Send the message without the Dialog

MAPIMessage.Save  'Save the Current Message

MultiMedia

You use the MultiMedia control to open and play one of the many types of MultiMedia files. The following capabilities are supported by the MultiMedia control:

NOTE

In order to create or use MultiMedia applications, your system must contain the correct hardware (such as a CD-ROM and a Sound Card).
NOTE

For a more in-depth look at MultiMedia, see Chapter 9, which concentrates on the MultiMedia applications.

You use the MultiMedia control to control the playback of the devices or files through a VCR-like user interface. To set up a MultiMedia control to play an audio compact disc, for example, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft MultiMedia control to your project.

  3. Double-click on the MultiMedia control MMControl in ToolTips display) contained in the toolbox to place a MultiMedia control on your form.

  4. Include the following property settings for the MultiMedia control:

    BackVisible= False
    Devicetype = CDAUDIO
    EjectEnabled = True
    NextEnabled = True
    PauseEnabled = True
    PlayEnabled = True
    PrevEnabled = True
    RecordVisible= False
    StepVisible = False
    StopEnabled = True

  5. Add the following code to the From_Load event:

    MMControl1.Command = "open" open the MM Device

  6. Add the following code to the mmcontrol1_NextClick event:

    MMControl1.Track = MMControl1.Track + 1

  7. Add the following code to the MMControl1_PlayClick event:

    MMControl1.Track = 1

  8. Add the following code to the MMControl1_PrevClick event:

    MMControl1.Track = MMControl1.Track - 1

  9. Add the following code to the MMControl1_StatusUpdate event:

    txtTrack.Text = " Track " & MMControl1.Track & " of " & MMControl1.Tracks & " Tracks

  10. Double-click on the TextBox control (TextBox in ToolTips display) contained in the toolbox to place a TextBox control on your form.

  11. Include the following property setting in the TextBox control:

    Name = txtTrack
    Height = 495
    Left = 2280
    Top = 780
    Width = 1215

  12. Press the F5 key to run the project. Figure 21.19 illustrates the MultiMedia control as it would appear on your display.


Figure 21.19. Using the MultiMedia control.

  1. Insert an audio CD into your CD drive.

  2. Click the Play button on the MultiMedia control.

The CD starts to play. You can Click the Move Forward button to move to the next song, or you can Click the Move Back button to move to the preceding song. Click the Eject button to open the CD drive door.

Click the Stop button before you end the project; otherwise, the CD continues to play.

Outline

You use the Outline control to group data into a hierarchical structure and to provide a visual indication of that structure.

The application used in this section uses the Publisher table as the master table or top level of the outline. The child or secondary level of the outline is Titles. The link between the two levels is the publisher's ID. Using that link, you can select the publisher to identify all the titles it has published.

To create the sample application using the Outline control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft Outline control to your project.

  3. Double-click on the Outline control (Outline in ToolTips display) contained in the toolbox to place a MultiMedia control on your form.

  4. Click and drag the top-left corner of the Outline control to the top-left corner of the form. Click and drag the bottom-right corner of the Outline control so that the Outline control occupies most of your form.

  5. Add the following code to the Form declarations section:

    Dim ws As Workspace
    Dim db As Database

  6. Add the following code to the Form_Load event:

    Dim rs As Recordset
    Set ws = DBEngine.CreateWorkspace("ws1", "Admin", "")
    Set db = ws.OpenDatabase("c:\vb40\biblio.mdb", False, False)
    Set rs = db.OpenRecordset("Select * from publishers order by name", dbOpenDynaset)
    'load the Publishers into the OutLine control

    Do While rs.EOF = False

    If Not IsNull(rs("name")) Then

    Outline1.AddItem rs("name")

    End If

    rs.MoveNext

    Loop

  7. Add the following code to the Outline1_DblClick event:

    Dim rs As Recordset
    Dim rspub As Dynaset

    If Outline1.Indent(Outline1.ListIndex) <> 1 Then
    Exit Sub
    End If

    If Outline1.HasSubItems(Outline1.ListIndex) = False Then

    Set rspub = db.OpenRecordset("select * from publishers where name ='" & Outline1.List(Outline1.ListIndex) & "'", dbOpenDynaset)

    If rspub.RecordCount > 0 Then

    Set rs = db.OpenRecordset("select * from titles where pubid = " & rspub("pubid"), dbOpenDynaset)

    If rs.RecordCount = 0 Then

    Exit Sub

    End If

    Do While rs.EOF = False

    Outline1.AddItem rs("title"), Outline1.ListIndex + 1
    Outline1.Indent(Outline1.ListIndex + 1) = 2
    rs.MoveNext

    Loop

    End If

    End If

    Outline1.Expand(Outline1.ListIndex) = True

  8. Add the following code to the Outline1_Keypress event:

    Select Case KeyAscii

    Case 13

    If Outline1.Expand(Outline1.ListIndex) = False Then

    Outline1_DblClick

    Else

    Outline1.Expand(Outline1.ListIndex) = False

    End If

    End Select

  9. Press the F5 key to run the project.

When the project starts, you see a list of publishers (see Figure 21.20). When you double-click on the publisher's name, a list of related books appears. When you click on the minus sign
(—), the list collapses. If subitems are associated with the publisher, a plus sign (+) appears next to the publisher's name. If you click on the plus sign, the list expands.


Figure 21.20. Using the Outline control.

Picture Clipping

You use the Picture Clipping control to select a bitmap from a file containing multiple bitmap images. You can use the Picture Clipping control to design bitmaps for each of the states of a button that appear in a toolbar. In order to reduce the physical number of files, the bitmaps are combined into one file. To access the pictures in your application, you use the Picture Clipping control to select the appropriate bitmap based on the state of the button.

To create the sample application using the Picture Clipping control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Microsoft PictureClip control to your project.

  3. Double-click on the PictureClip control (PictureClip in ToolTips display) contained in the toolbox to place a PictureClip control on your form.

  4. Include the following property settings for the PictureClip control:

    Name = PictureClip1
    Left = 300
    Top = 300
    Rows = 4
    Cols = 6
    Picture = c:\vb40\book\chp21\toolbar.bmp

  5. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Sheridan 3D Controls to your project.

  6. Double-click on the 3D Command Button control (SSCommand in ToolTips Display) contained in the toolbox to place two 3D Command Buttons on your form.

  7. Include the following property settings for the PictureClip control:

    3D Command button 1

    Name = cmdPrint
    Height = 495
    Left = 240
    Top = 120
    Width = 1215
    AutoSize = 2

    3D Command button 2

    Name = cmdHelp
    Height = 495
    Left = 1860
    Top = 120
    Width = 1215
    AutoSize = 2

  8. Add the following code to the Form_Load event:

    cmdHelp.picture = PictureClip1.GraphicCell(6)
    cmdPrint.picture = PictureClip1.GraphicCell(5)

  9. Press the F5 key to run the project.

When the project starts, bitmap number 5 from the picture clip control will be loaded as the picture for the cmdPrint command button; picture number 6 will be loaded as the picture for the cmdHelp button (see Figure 21.21).


Figure 21.21. Using the PictureClip control.

Spin

You use the Spin control with another control to give the user a visible method of incrementing or decrementing a value in an associated control.

NOTE

The following example builds on the example presented in the MaskEdit TextBox section.

To use the Spin control with the MaskEdit TextBox control, follow these steps:

  1. Open the project containing the MaskEdit control example using the File | Open project command.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Outrider SpinButton control to your project.

  3. Double-click on the SpinButton control (SpinButton in ToolTips display) contained in the toolbox to place a SpinButton control on your form.

  4. Set the Name property to spnDate.

  5. Add the following code to the spnDate_Spindown event:

    txtDate.Text = CVDate(txtDate.Text) - 1

  6. Add the following code to the spnDate_Spinup event:

    txtDate.Text = CVDate(txtDate.Text) + 1

  7. Press the F5 key to run the project.

Once the project is running, click the Spin buttons (see Figure 21.22). When you click the Spin Up button, the value of the date increases. When you click the Spin Down button, the value of the date decreases.


Figure 21.22. Using the Spin control.

Tabbed

The Tabbed Dialog control provides a Tabbed dialog box (see Figure 21.23), much like those seen in other Microsoft products (Word, for example). The Tabbed Dialog control enables you to grant users access to a large amount of information on one form without needlessly cluttering up the screen. By using the Tabbed Dialog control, you can group similar items together and allow the users to quickly switch between the types of items they want to access.


Figure 21.23. Word 6.0 Tabbed dialog box.

The following example will utilize a Tabbed dialog in order to display information from the BIBLIO database. Tab one will contain publisher information; Tab two will contain book information. When you select the book tab, you will see only books relating to the publisher currently displayed on Tab one.

To create the sample application using the Tabbed Dialog control, follow these steps:

  1. Using the File | New Project command, open a new project.

  2. Follow the steps outlined in the "Adding Custom Controls to Your Project" section to add the Sheridan Tabbed Dialog control to your project.

  3. Double-click on the Tabbed Dialog control (SSTab in ToolTips display) contained in the toolbox to place a Tabbed Dialog control on your form.

  4. Include the following property settings for the Tabbed Dialog control:

    Name = SSTab1
    Height = 3075
    Left = 0
    Top = 0
    Width = 6195
    TabsPerRow = 3
    Tabs = 2
    Style = 0

    In order to place controls on a specific tab, you need to first select the tab where the controls are to be placed, then double-click the control that you want to place on the tab.

  5. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your Tabbed dialog.

  6. Include the following property settings for the Data control:

    Name = dtaPublishers
    Caption = "Publishers"
    DatabaseName = "c:\vb40\biblio.mdb"
    Height = 300
    Left = 420
    RecordSource = "Publishers"
    Top = 2580
    Width = 5475

  7. Double-click on the TextBox control (Data in ToolTips display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  8. Include the following property settings for the TextBox control:

    Name = txtState
    DataField = "State"
    DataSource = "dtaPublishers"
    Height = 375
    Left = 4740
    Top = 2100
    Width = 1215

  9. Double-click on the TextBox control (Data in ToolTips display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  10. Include the following property settings for the TextBox control:

    Name = txtCity
    DataField = "City"
    DataSource = "dtaPublishers"
    Height = 375
    Left = 2340
    Top = 2100
    Width = 1215

  11. Double-click on the TextBox control (Data in ToolTips display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  12. Include the following property settings for the TextBox control:

    Name = txtAddress
    DataField = "Address"
    DataSource = "dtaPublishers"
    Height = 735
    Left = 2340
    Top = 1260
    Width = 3675

  13. Double-click on the TextBox control (Data in ToolTips display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  14. Include the following property settings for the TextBox control:

    Name = txtName
    DataField = "Name"
    DataSource = "dtaPublishers"
    Height = 315
    Left = 2340
    Top = 780
    Width = 3675

  15. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your Tabbed dialog.

  16. Include the following property settings for the Label control:

    Name = lblState
    Caption = "State"
    Height = 300
    Left = 3840
    Top = 2160
    Width = 735

  17. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your Tabbed dialog.

  18. Include the following property settings for the Label control:

    Name = lblCity
    Caption = "City"
    Height = 300
    Left = 540
    Top = 2160
    Width = 1215

  19. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your Tabbed dialog.

  20. Include the following property settings for the Label control:

    Name = lblAddress
    Caption = "Address"
    Height = 300
    Left = 540
    Top = 1260
    Width = 1215

  21. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your Tabbed dialog.

  22. Include the following property settings for the Label control:

    Name = lblPublisher
    Caption = "Publisher"
    Height = 295
    Left = 540
    Top = 780
    Width = 1215

  23. Double-click on the Data control (Data in ToolTips display) contained in the toolbox to place a Data control on your Tabbed dialog.

  24. Include the following property settings for the Data control:

    Name= dtaBooks
    Caption = "Books"
    DatabaseName = "c:\vb40\biblio.mdb"
    Height = 300
    Left = 420
    Options = 0
    RecordSource = "Titles"
    Top = 2640
    Width = 5475

  25. Double-click on the TextBox control (Data in ToolTips Display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  26. Include the following property settings for the TextBox control:

    Name = txtDescription
    DataField = "Description"
    DataSource = "dtaBooks"
    Height = 315
    Left = 2280
    Top = 1080
    Width = 3675

  27. Double-click on the TextBox control (Data in ToolTips Display) contained in the toolbox to place a TextBox control on your Tabbed dialog.

  28. Include the following property settings for the TextBox control:

    Name = txtTitle
    DataField = "Title"
    DataSource = "dtaBooks"
    Height = 315
    Left = 2280
    Top = 660
    Width = 3675

  29. Double-click on the Label control (Label in ToolTips Display) contained in the toolbox to place a Label control on your Tabbed dialog.

  30. Include the following property settings for the Label control:

    Name= lblDescription
    Caption = "Description"
    Height = 300
    Left = 360
    TabIndex = 12
    Top = 1140
    Width = 1215

  31. Double-click on the Label control (Label in ToolTips display) contained in the toolbox to place a Label control on your Tabbed dialog.

  32. Include the following property settings for the Label control:

    Name = lblTitle
    Caption = "Title"
    Height = 300
    Left = 360
    Top = 720
    Width = 1215

  33. Add the following code to the Form_Load event:

    SSTab1.TabCaption(0) = "Publishers"
    SSTab1.TabCaption(1) = "&Books"

  34. Add the following code to the SSTab1_Click event:

    If PreviousTab = 0 Then

    dtaBooks.RecordSource = "select * from titles where pubid= " &_ dtaPublishers.Recordset("pubid")
    dtaBooks.Refresh
    End If

  35. Press the F5 key to run the project.

Once the project is running, select a publisher using the Data Control on the first tab (see Figure 21.24). Select the second Tab, and you should now be able to move through the books from the publisher on the first Tab.


Figure 21.24. Using the Tabbed dialog.

Summary

In this chapter, you looked at what custom controls are, and how you can use them in your projects to improve the application's user interface and its functionality. You also looked at some brief examples using the controls bundled with Visual Basic. Chapter 30 looks at some of the available third-party controls.

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