Visual Basic Source Code/Visual Basic Source Code.iso/vbsource/refres/refresh.frm

Text File | 1995-05-08 | 7KB | 195 lines

VERSION 2.00
Begin Form Form1
   AutoRedraw      =   -1  'True
   BackColor       =   &H00808000&
   Caption         =   "REFRESH DEMO"
   ClientHeight    =   4125
   ClientLeft      =   960
   ClientTop       =   1770
   ClientWidth     =   5010
   ForeColor       =   &H00000000&
   Height          =   4815
   Icon            =   REFRESH.FRX:0000
   Left            =   900
   LinkMode        =   1  'Source
   LinkTopic       =   "Form1"
   MaxButton       =   0   'False
   ScaleHeight     =   4125
   ScaleWidth      =   5010
   Top             =   1140
   Width           =   5130
   Begin TextBox txbRefreshed
      BackColor       =   &H0000C000&
      ForeColor       =   &H00000000&
      Height          =   615
      Left            =   240
      TabIndex        =   3
      TabStop         =   0   'False
      Top             =   3120
      Width           =   4500
   End
   Begin TextBox txbRefComment
      BackColor       =   &H00808000&
      FontBold        =   -1  'True
      FontItalic      =   -1  'True
      FontName        =   "MS Sans Serif"
      FontSize        =   8.25
      FontStrikethru  =   0   'False
      FontUnderline   =   0   'False
      ForeColor       =   &H00000000&
      Height          =   285
      Left            =   2520
      TabIndex        =   7
      TabStop         =   0   'False
      Top             =   2760
      Width           =   2175
   End
   Begin TextBox txbNonRefreshed
      BackColor       =   &H000000FF&
      ForeColor       =   &H00000000&
      Height          =   615
      Left            =   240
      TabIndex        =   2
      TabStop         =   0   'False
      Top             =   1800
      Width           =   4500
   End
   Begin TextBox txbNonRefComment
      BackColor       =   &H00808000&
      FontBold        =   -1  'True
      FontItalic      =   -1  'True
      FontName        =   "MS Sans Serif"
      FontSize        =   8.25
      FontStrikethru  =   0   'False
      FontUnderline   =   0   'False
      ForeColor       =   &H00000000&
      Height          =   285
      Left            =   2520
      TabIndex        =   8
      TabStop         =   0   'False
      Top             =   1440
      Width           =   2175
   End
   Begin TextBox txbWidthValue
      BackColor       =   &H00808000&
      BorderStyle     =   0  'None
      FontBold        =   -1  'True
      FontItalic      =   0   'False
      FontName        =   "MS Sans Serif"
      FontSize        =   12
      FontStrikethru  =   0   'False
      FontUnderline   =   0   'False
      ForeColor       =   &H00000040&
      Height          =   375
      Left            =   3840
      TabIndex        =   0
      TabStop         =   0   'False
      Text            =   "4500"
      Top             =   360
      Width           =   735
   End
   Begin CommandButton cmbDemo
      BackColor       =   &H0000FFFF&
      Caption         =   "START DEMO"
      Height          =   615
      Left            =   240
      TabIndex        =   1
      Top             =   240
      Width           =   1695
   End
   Begin Label Label2
      BackColor       =   &H00808000&
      Caption         =   "Changing Width Value Using Explicit Refresh."
      Height          =   375
      Left            =   240
      TabIndex        =   5
      Top             =   2640
      Width           =   2175
   End
   Begin Label Label1
      BackColor       =   &H00808000&
      Caption         =   "Changing Width Value With VB's Idle Refresh."
      Height          =   375
      Left            =   240
      TabIndex        =   4
      Top             =   1320
      Width           =   2175
   End
   Begin Label Label3
      BackColor       =   &H00808000&
      Caption         =   "Width ="
      FontBold        =   -1  'True
      FontItalic      =   0   'False
      FontName        =   "MS Sans Serif"
      FontSize        =   12
      FontStrikethru  =   0   'False
      FontUnderline   =   0   'False
      Height          =   375
      Left            =   2880
      TabIndex        =   6
      Top             =   360
      Width           =   975
   End
   Begin Menu mnuHelp
      Caption         =   "&Help"
      Begin Menu mnuNotes
         Caption         =   "&Notes..."
      End
      Begin Menu mnuAbout
         Caption         =   "&About..."
      End
   End
End
Const ttlHelpAbout$ = "Who Done It?"
Const msgHelpAbout$ = "Just for fun - Peter Hartquist 73227,3600"
Const ttlHelpNotes$ = "What Does It Do?"
Const msgHelpNotes$ = "According the the Language Reference manual, refreshing a form or control happens automatically when VB's idle loop is reached.  This demo shows the effect of explicitly using Refresh on a dynamically changing control."

'
'   According the the Visual Basic Language Reference manual, refreshing
'   a form or control happens automatically when VB's idle loop is reached.
'   In this example I have created a situation to demonstrate
'   the effects of using or not using Refesh on a control
'   (a text box) while it repetitively changes in width.
'
'   I have created two similar controls on the form.  One text box changes
'   without using Refresh and one changes with Refresh on each change.
'
'   It looks like Refresh is not necessary when decreasing the width of a
'   text box control.  It actually causes jitter in the redrawn image.
'   But Refresh is needed to see the effects of repetitively increasing
'   the width of the text box.  Without Refresh, the text box doesn't
'   display with its' correct width until the repetitive changes have
'   all been completed.
'
'
Sub cmbDemo_Click ()
    cmbDemo.Enabled = False
    txbNonRefComment.Text = "Smooth"  'Comments while
    txbRefComment.Text = "Jitters a bit"    'Width decreases
    For I = -4500 To 4500 Step 50     'Initial Textbox Width = 4500
    If Abs(I) < 250 Then              'Handle low wdith value
    I = 250                           'Avoid low or zero I value
    txbNonRefComment.Text = "Wrong Width" 'Comments while
    txbRefComment.Text = "Correct Width"  'Width increases
    End If                            '
    txbWidthValue.Text = Str$(Abs(I)) 'Display Width Value
    txbNonRefreshed.width = Abs(I)    'Change Textbox 1 without Refresh
    txbRefreshed.width = Abs(I)       'Change Testbox 2
    txbRefreshed.Refresh              'With Refresh
    Next I                            'Loop till done
    txbNonRefComment.Text = "Correct Width At Last" 'Comments
    txbRefComment.Text = "Correct Width"            'when done
    cmbDemo.Enabled = True
    cmbDemo.Caption = "SEE IT AGAIN ?"
End Sub

Sub mnuAbout_Click ()
    MsgBox msgHelpAbout$, 64, ttlHelpAbout$
End Sub

Sub mnuNotes_Click ()
    MsgBox msgHelpNotes$, 64, ttlHelpNotes$
End Sub