Q171812: FIX: Run-Time Error When DataObject Passed as Object

Article: Q171812
Product(s): Microsoft Visual Basic for Windows
Version(s): WINDOWS:5.0
Operating System(s): 
Keyword(s): kbVBp500 kbVS97sp2fix kbGrpDSVB kbvbp500sp2fix
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Learning Edition for Windows, version 5.0 
- Microsoft Visual Basic Professional Edition for Windows, version 5.0 
- Microsoft Visual Basic Enterprise Edition for Windows, version 5.0 
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SYMPTOMS
========

When you pass a DataObject as an Object to another procedure, you receive one of
the following errors:

  Run-time error '-2147417848 (80010108)':
  Method 'GetFormat' of object 'IVBDataObject' failed

  - or -

  Run-time error '-2147319765 (8002802b)':
  Automation Error

RESOLUTION
==========

This problem is corrected with Microsoft Visual Studio 97 Service Pack 2.

You may also work around this issue by obtaining the correct interface to the
DataObject that contains the GetFormat method. The example below illustrates
this workaround. In this example, the DataObject is passed to a subroutine as an
Object and is then set to a variable of type MSFlexGridLib.DataObject:

     Private Sub MSFlexGrid1_OLEDragDrop( _
        Data As msflexgridlib.DataObject, Effect As Long, Button As _
        Integer, Shift As Integer, x As Single, y As Single)
        PrintIt Data
     End Sub

     Sub PrintIt(d As Object)
         Dim iDataObject As MSFlexGridLib.DataObject
         Set iDataObject = d
         Debug.Print iDataObject.GetFormat(vbCFText)
     End Sub

This method allows you to communicate directly with the DataObject interface of
the Object that is passed to the PrintIt procedure.

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 97 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
================

This error may occur with ActiveX controls that support OLE drag-and-drop. The
error does not occur with intrinsic controls.

The following list contains some ActiveX controls that exhibit this problem:

  Animation
  FlexGrid
  ListView
  Masked EditBox
  Progress Bar
  Rich TextBox
  Slider
  SSTab
  StatusBar
  TabStrip
  Toolbar
  TreeView
  UpDown

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

1. Open a new "Standard EXE" project.

2. Click Components on the Project menu. Check "Microsoft FlexGrid Control 5.0."

3. Add a TextBox to Form1. Set the OLEDragMode property to 1-Automatic and the
  OLEDropMode to 1-Manual.

4. Add a FlexGrid to Form1. Set the OLEDropMode to 1-flexOLEDropManual.

5. Add the following code to Form1:

        Private Sub MSFlexGrid1_OLEDragDrop( _
           Data As msflexgridlib.DataObject, Effect As Long, Button As _
           Integer, Shift As Integer, x As Single, y As Single)
           PrintIt Data
        End Sub

        Sub PrintIt(d As Object)
           Debug.Print d.GetFormat(vbCFText)
        End Sub

        Private Sub Text1_OLEDragDrop(Data As DataObject, Effect As Long, _
           Button As Integer, Shift As Integer, x As Single, y As Single)
           PrintIt Data
        End Sub
   

6. Press the F5 key to run the application.

7. Highlight the text in the TextBox, then drag-and-drop it on top of itself. As
  expected, "True" is printed to the Immediate window.

8. Highlight the text in the TextBox, then drag-and-drop it on top of the
  FlexGrid. You receive the following error:

  Run-time error '-2147417848 (80010108)':
  Method 'GetFormat' of object 'IVBDataObject' failed

Additional query words:

======================================================================
Keywords          : kbVBp500 kbVS97sp2fix kbGrpDSVB kbvbp500sp2fix 
Technology        : kbVBSearch kbAudDeveloper kbZNotKeyword6 kbZNotKeyword2 kbVB500Search kbVBA500 kbVB500
Version           : WINDOWS:5.0
Issue type        : kbbug
Solution Type     : kbfix

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