BUG: IPF Referencing Default Property of Nonexistent Image Ctrl

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 6.0

SYMPTOMS

When you try to access the default property of a nonexistent Image Control in a control array in Visual Basic 6.0, an Invalid Page Fault (IPF) or application error occurs instead of a run-time error.

RESOLUTION

Specify the Picture property of the Image1(<index>).Picture explicitly, instead of depending on the default property.

STATUS

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

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new Standard EXE Project. Form1 is created by default.



2. Place an Image Control on Form1.



3. Set the Index Property of the Image Control to "0."



4. Add the following code in the General Declarations section of Form1:

   
         Private Sub Form_Load()
            Dim p As StdPicture
            Set p = Pic()
         End Sub
   
         Private Function Pic() As StdPicture
            Set Pic = Image1(1) ' NOTE THAT IMAGE1(1) DOESN'T EXIST!
         End Function 




5. Press the F8 key to start the project. Press F8 to step through the project.



6. Close Form1.



7. Repeat steps 5 and 6 several times to get the IPF.



8. To avoid the page fault, specify Image1(1).Picture explicitly instead of depending on the default property. So, repeat steps 1 through 4, replacing the Pic Function with the following:

   
         Private Function Pic() As StdPicture
            Set Pic = Image1(1).Picture
         End Function 




9. Run the project.

Run-time Error '340:
Control array element '1' doesn't exist

Additional query words: GPF IPF

Keywords : kbCtrl kbVBp600bug kbGrpVB
Version : WINDOWS:6.0
Platform : WINDOWS
Issue type : kbbug