HOWTO: Create a Setup-Like Status Bar in Visual Basic

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, versions 5.0, 6.0
• Microsoft Visual Basic Standard, Professional, and Enterprise Editions for Windows, version 4.0

SUMMARY

Many applications use a status bar to display the progress of an installation or other lengthy process. Often the percent completed is printed in the middle of the bar and it changes color as the status bar passes over it. This article illustrates how to achieve this effect using Visual Basic for Windows. As a note, the professional and enterprise edition contain a progress bar control that could be used instead. For Win16 applications, the sample calldlls in vb\samples\calldlls uses shape controls to achieve the same effect.

MORE INFORMATION

The simplest way to specify the range of the status bar is to determine what the zero-based range will be and specify that value as the ScaleWidth of the horizontal scroll bar. Then you don't have to scale the data for each new sample.

Changing the color of the percentage displayed within the picture box is done by specifying the DrawMode as Not XOR Pen with a compatible background. When the bar is drawn, an exclusive OR is performed on each pixel. If the pixel is red, it is made white and vice versa. The text must be placed first because Print does not support DrawMode. The following program demonstrates how to display a red status bar with a red or white text message centered in it. Colors other than red are specified by changing the ForeColor property of the Picture Box Control.

Step-by-Step Example

1. Start a new project in Visual Basic. Form1 is created by default.



2. Add a picture box (Picture1) and a command button (Command1) to the form.



3. Add the following code to the general declarations section of Form1:

   
   Dim tenth As Long
   
   #If Win32 Then
   Private Declare Function BitBlt Lib "gdi32" _
   (ByVal hDestDC As Long, ByVal x As Long, ByVal y As Long, _
   ByVal nWidth As Long, ByVal nHeight As Long, _
   ByVal hSrcDC As Long, ByVal xSrc As Long, ByVal ySrc As Long, _
   ByVal dwRop As Long) As Long
   #Else
   Private Declare Function BitBlt Lib "GDI" (ByVal hDestDC As _
   Integer, ByVal x As Integer, ByVal y As Integer, ByVal nWidth _
   As Integer, ByVal nHeight As Integer, ByVal hSrcDC As Integer, _
   ByVal xSrc As Integer, ByVal ySrc As Integer, ByVal dwRop As _
   Long) As Integer
   #End If
   
   Sub UpdateStatus(FileBytes As Long)
   '--------------------------------------------------------------------
   ' Update the Picture1 status bar
   '--------------------------------------------------------------------
       Static progress As Long
       Dim r As Long
       Const SRCCOPY = &HCC0020
       Dim Txt$
       progress = progress + FileBytes
       If progress > Picture1.ScaleWidth Then
           progress = Picture1.ScaleWidth
       End If
       Txt$ = Format$(CLng((progress / Picture1.ScaleWidth) * 100)) + "%"
       Picture1.Cls
       Picture1.CurrentX = _
       (Picture1.ScaleWidth - Picture1.TextWidth(Txt$)) \ 2
       Picture1.CurrentY = _
       (Picture1.ScaleHeight - Picture1.TextHeight(Txt$)) \ 2
       Picture1.Print Txt$
       Picture1.Line (0, 0)-(progress, Picture1.ScaleHeight), _
       Picture1.ForeColor, BF
       r = BitBlt(Picture1.hDC, 0, 0, Picture1.ScaleWidth, _
           Picture1.ScaleHeight, Picture1.hDC, 0, 0, SRCCOPY)
   End Sub
   
   Private Sub Command1_Click()
       Picture1.ScaleWidth = 109
       tenth = 10
       For i = 1 To 11
           Call UpdateStatus(tenth)
           x = Timer
           While Timer < x + 0.75
               DoEvents
           Wend
       Next
   End Sub
   
   Private Sub Form_Load()
       Picture1.FontBold = True
       Picture1.AutoRedraw = True
       Picture1.BackColor = vbWhite
       Picture1.DrawMode = 10
       Picture1.FillStyle = 0
       Picture1.ForeColor = vbBlue
   End Sub 




4. Select F5 to run the program, and then click Command1.

REFERENCES

Visual Basic Setup Wizard file SETUP1.BAS.

Additional query words:

Keywords : kbAPI kbSDKWin32 kbVBp kbVBp400 kbVBp600 kbGrpVB kbDSupport
Version : WINDOWS:4.0,5.0,6.0
Platform : WINDOWS
Issue type : kbhowto