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Q223118: FIX: PSET Method Is Slower in Visual Basic 6.0

Article: Q223118
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:6.0
Operating System(s): 
Keyword(s): kbservicepack kbCompiler kbVBp500 kbVBp600bug kbGrpDSVB kbVS600sp2 kbVS600SP1 kbVS600sp
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, version 6.0 
- Microsoft Visual Basic Professional Edition for Windows, version 6.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 6.0 
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SYMPTOMS
========

A project created in Visual Basic 5.0 uses the PSet method to change the color
of pixels in an object. The project is compiled into an executable file using
Visual Basic 5.0. When the same project is compiled using Visual Basic 6.0, the
executable file runs noticeably slower than the Visual Basic 5.0 version. The
expected behavior is that the Visual Basic 6.0 application should run at least
as fast as the Visual Basic 5.0 application.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article.

This bug was corrected in Visual Studio 6.0 Service Pack 3. For more information
about Visual Studio service packs, please see the following articles in the
Microsoft Knowledge Base:

Q194022 INFO: Visual Studio 6.0 Service Packs, What, Where, Why

Q194295 HOWTO: Tell That Visual Studio 6.0 Service Packs Are Installed

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

This section demonstrates how to create a sample project that reproduces the bug
behavior. It assumes that you have Visual Basic 5.0 and 6.0 installed on the
same or identical machines. It also assumes that you are familiar with the PSet
Method and compiling projects. If you are not familiar with these tasks, see the
REFERENCES section below for more information.

Steps to Reproduce Behavior
---------------------------

1. Start a new Visual Basic 5.0 Standard EXE project. Form1 is created by
  default.

2. Add a PictureBox, a CommandButton, and a Label control to Form1. Position the
  Label control so that there is ample room to its right to accommodate 40
  characters.

3. Copy the following code to the General Declarations section of Form1:

  Option Explicit

  Private Sub Command1_Click()
     Dim dStart As Double
     Dim dEnd As Double
     Dim intX As Integer
     Dim intY As Integer
     
     Picture1.Cls
     dStart = Timer
     For intY = 1 To Picture1.ScaleHeight
        For intX = 1 To Picture1.ScaleWidth
           Picture1.PSet (intX, intY), vbBlue
        Next
     Next
     dEnd = Timer
     Label1.Caption = "Elapsed time: " & dEnd - dStart & " seconds."
  End Sub

  Private Sub Form_Load()
     With Picture1
        .ScaleMode = 3
        .TabIndex = 1
        .Top = 120
        .Width = 4215
     End With
     Label1.AutoSize = True
  End Sub

4. Compile the project into an executable file. Run the executable file and
  click the CommandButton. Note the time shown in the Label control.

5. Open the same project in Visual Basic 6.0. Compile the project into an
  executable file. Run the Visual Basic 6.0 executable file version and click
  the Command Button.

  BUG: The Visual Basic 6.0 version is slower the Visual Basic 5.0 version.

REFERENCES
==========

Please see:

- Topics on Compiling Applications in the Online Help, or the Microsoft Visual
  Basic 6.0 Component Tools Guide, or the MSDN Web site at:
  http://msdn.microsoft.com/library/devprods/vs6/vb/html/vbmscstepintocompilingyourapplication.htm
  for more information about compiling your Visual Basic project.

- PSet Method in the Online Help, or the Microsoft Visual Basic 6.0 Component
  Tools Guide, or the MSDN Web site at:
  http://msdn.microsoft.com/library/devprods/vs6/vb/html/vamthpset.htm explains
  the PSet method.

Additional query words:

======================================================================
Keywords          : kbservicepack kbCompiler kbVBp500 kbVBp600bug kbGrpDSVB kbVS600sp2 kbVS600SP1 kbVS600sp3fix 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB600Search kbVBA600 kbVB600
Version           : WINDOWS:6.0
Issue type        : kbbug
Solution Type     : kbfix

=============================================================================

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