VB3 How to Create a Setup-like Status Bar in Visual Basic

- Standard and Professional Editions of Microsoft Visual Basic for

  Windows, version 3.0

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.

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 Form_Load event:

      Sub Form_Load()
         Picture1.AutoRedraw = True
         Picture1.BackColor  = &H80000003&
         Picture1.DrawMode   = 10
         Picture1.FillStyle  = 0
         Picture1.ForeColor  = &H00000080
      End Sub
   
   

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

   Dim tenth as Long

      ' Enter the following Declare statement as one, single line:
      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
   
      Sub UpdateStatus (FileBytes As Long)
   
         '--------------------------------------------------------------------
         ' Update the Picture1 status bar
         '--------------------------------------------------------------------
          Static progress 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
   
          ' Enter the following two lines as one, single line of code:
          Picture1.CurrentX =
             (Picture1.ScaleWidth - Picture1.TextWidth(Txt$)) \ 2
   
          ' Enter the following two lines as one, single line of code:
          Picture1.CurrentY =
             (Picture1.ScaleHeight - Picture1.TextHeight(Txt$)) \ 2
   
          Picture1.Print Txt$
   
          ' Enter the following two lines as one, single line of code:
          Picture1.Line (0,0)-(progress,Picture1.ScaleHeight),
             Picture1.ForeColor,BF
   
          ' Enter the following two lines as one, single line of code:
          r = BitBlt(Picture1.hDC, 0, 0,Picture1.ScaleWidth,
             Picture1.ScaleHeight, Picture1.hDC, 0, 0, SRCCOPY)
   
      End Sub
   
   

5. Add the following code to Click event procedure of Command1:

      Sub Command1_Click ()
         Picture1.ScaleWidth = 109
         tenth = 10
         For i = 1 to 10
            Call UpdateStatus(tenth)
            x = timer
            While Timer < x + .75
               doevents
            Wend
         Next
      End Sub
   
   

6. Press the F5 key to run the program, and then click the Command1 button.

REFERENCES

Visual Basic Setup Wizard file SETUP1.BAS.