BUG: GPF When RecordSource Property is Blank at Design-Time

• Microsoft Visual Basic Standard, Professional, and Enterprise Editions, 16-bit and 32-bit, for Windows, version 4.0

SYMPTOMS

A data control causes an application error at runtime if the data control contains with a blank RecordSource property at design time and the UpdateControls method is executed. The application error ends Visual Basic.

WORKAROUND

To work around this bug, at design time, set the data control's DatabaseName property to a database and the RecordSource property to a table in the database. Other controls that are bound to the data control, such as a text box, should also have a value in the control's DataSource property

STATUS

Microsoft has confirmed this to be a problem in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

MORE INFORMATION

Steps to Reproduce Problem

1. Start Visual Basic 4.0, or if it is already running, click New Project on the File menu.



2. Add a data control to the Form1 form but don't set any of the data control's properties.



3. Copy the following code sample to the Form1 code window:

   
         Private Sub Form_Click()
            Data1.updatecontrols
         End Sub 




4. Press the F5 key or click Start on the Run menu to start the program.



5. Click on the form. The application error occurs with one of the following error messages and Visual Basic ends. 32-bit edition of Visual Basic 4.0:

   
         Windows NT: An application error has occurred and an application
                     error log is being generated. VB32.exe, Exception: Access
                     violation (0xc0000005), Address: 0x0047929e 

   
         Windows 95: VB32 caused an invalid page fault in module VB32.EXE at
                     0137:0047929e. 

   
         16-bit edition of Visual Basic 4.0 in all operation systems:
                     VB caused a general protection fault in module VB.EXE at
                     0028:000026b9. 

Additional query words: kbVBp400bug kbDSupport

Keywords :
Version : 4.00
Platform : NT WINDOWS
Issue type : kbbug