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Q171829: FIX: GetChunk Freezes Unless Other Events Happening

Article: Q171829
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0
Operating System(s): 
Keyword(s): kbVBp500 kbVS97sp2fix kbvbp500sp2fix
Last Modified: 24-OCT-2000

-------------------------------------------------------------------------------
The information in this article applies to:

- Microsoft Visual Basic Enterprise Edition for Windows, version 5.0, on platform(s):
   - the hardware: DEC Alpha 
-------------------------------------------------------------------------------

SYMPTOMS
========

The GetChunk operation pauses unless other events are happening. Other events
could include moving the mouse, which would trigger the GetChunk to continue.

STATUS
======

Microsoft has confirmed this to be a bug in the Microsoft products listed at the
beginning of this article. This bug has been fixed in Visual Studio 97 Service
Pack 2.

For more information on the Visual Studio Service Pack 2, please see the
following article in the Microsoft Knowledge Base:

  Q170365 : INFO: Visual Studio 97 Service Packs - What, Where, and Why

For a list of the Visual Basic 5.0 bugs that were fixed in the Visual Studio 97
Service Pack 2, please see the following article in the Microsoft Knowledge
Base:

  Q171554 : INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2

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

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

1. Run Visual Basic or, if Visual Basic is already running, choose New Project
  from the File menu (ALT, F, N). Form1 is created by default. Add the
  following code to the General Declarations of Form1:

        Option Explicit
        Private bwait As Boolean

2. Place an Internet Transfer Control (Inet1) on Form1, and add the following
  code:

        Private Sub Inet1_StateChanged(ByVal State As Integer)
          Dim s$, t$
          Debug.Print "StateChanged:", State
          If State = icResponseCompleted Then
             t$ = ""
             s$ = Inet1.GetChunk(1024)
             DoEvents
             While Len(s$) <> 0
                 t$ = t$ & s$
                 s$ = Inet1.GetChunk(1024)
                 DoEvents: DoEvents: DoEvents
                 Debug.Print ".";
             Wend
             Debug.Print
             Debug.Print Left$(t$, 20), Len(t$)
             bwait = True
          End If
        End Sub

3. Place a CommandButton (Command1) on Form1, and add the following code:

        Private Sub Command1_Click()
           Dim i As Integer
           Dim tmp As Single

           For i = 1 To 5
            tmp = Timer
            While tmp + 1 > Timer
                 DoEvents: DoEvents: DoEvents
            Wend
            bwait = False
            Inet1.Execute "http://msw"
            While Not (bwait)
             DoEvents
            Wend
           Next
        End Sub

4. Press the F5 key to run it, and then press the ENTER key to invoke the
  command_click. (NOTE: Do not move the mouse or touch the keyboard.)

5. Watch your debug window. The first time you access the page, it works.
  However, the second time, you need to pause. Press Ctrl-break quickly and you
  are at the Doevents statement following the GetChunk. If you move the mouse,
  the GetChunk will continue.

Additional query words:

======================================================================
Keywords          : kbVBp500 kbVS97sp2fix kbvbp500sp2fix 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2
Version           : WINDOWS:5.0
Hardware          : ALPHA
Issue type        : kbbug
Solution Type     : kbfix

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

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