Q150219: BUG: Progress Bar Does Not Paint When DragMode Automatic

Article: Q150219
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:4.0
Operating System(s): 
Keyword(s): kbVBp400bug
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SYMPTOMS
========

If the DragMode property of the Microsoft Windows 95 Progress Bar control is set
to 1-Automatic, it does not paint if the progress of the control is updated.

STATUS
======

Microsoft has confirmed this to be an issue in the Microsoft products listed at
the beginning of this article.

RESOLUTION
==========

Set DragMode to 0-Manual before progress is updated, and then reset it to 1-
Automatic after the control has had time to paint.

Instead of updating the value directly, the following subroutine can be called to
update the value. The first parameter is the control itself and the second
parameter is the new value for the progress:

     Public Sub UpdateProgress(ProgBar As Object, NewValue As Integer)
        'Turn drag to Manual briefly.
        ProgBar. Value = 0
        'Update the progress.
        ProgBar.Value = NewValue
        'Turn drag to Automatic, and allow time for repaint.
        ProgBar.DragMode = 1
        DoEvents
     End Sub

MORE INFORMATION
================

Steps to Reproduce Problem
--------------------------

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

2. Place a progress bar control on Form1. Change the DragMode property to
  1-Automatic.

3. In the Click event of Form1, place the following code:

        Private Sub Form_Click()
           For i = 1 To 10
              ProgressBar1.Value = ProgressBar1.Value + 10
           Next i
        End Sub

4. Run the project by pressing the F5 key. Click the form, and note that nothing
  happens. If DragMode was initially set to 0-Manual, then progress is shown
  until the bar fills.

To work around the problem above, include the UpdateProgess subroutine in the
code of Form1, and modify the Click event of the Form to the following:

     Private Sub Form_Click()
        For i = 1 To 10
           UpdateProgress ProgressBar1, ProgressBar1.Value + 10
        Next i
     End Sub

Additional query words: 4.00 vb4win vb432 buglist4.00

======================================================================
Keywords          : kbVBp400bug 
Technology        : kbVBSearch kbAudDeveloper kbVB400Search kbVB400
Version           : WINDOWS:4.0
Issue type        : kbbug

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