DOCUMENT:Q181889  04-MAR-1998  [vbwin]
TITLE   :BUG: VB Hangs While Automating Excel Using OLE Control
PRODUCT :Microsoft Visual Basic for Windows
PROD/VER:WINDOWS:5.0,97
OPER/SYS:WINDOWS
KEYWORDS:vb5all VBKBAutomation

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

 - Microsoft Visual Basic Learning, Professional, and Enterprise Editions
   for Windows, version 5.0
 - Microsoft Excel 97 for Windows
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SYMPTOMS
========

Your application hangs while automating Microsoft Excel 97 via the OLE
control.

CAUSE
=====

This problem occurs while automating a Microsoft Excel 97 object that is
using in-place activation in an OLE control. The problem does not occur
with all methods or properties. This problem has been reported with the
following method/properties in the Microsoft Excel object library:

   PrintOut
   Delete

RESOLUTION
==========

A workaround is to not activate the object while running the automation
code. However, if you need to activate the object, do so in a separate
window instead of using in-place activation. For example, this line
activates the object in a separate window:

   OLE1.DoVerb vbOLEOpen

Another workaround is to deactivate the object before calling the
automation code that causes Visual Basic to hang. For example, the PrintOut
and Delete methods cause this problem to occur. Before using these methods,
you can deactivate the object prior to calling the method, then optionally
reactivate the object after calling the method. See the MORE INFORMATION
section later in this article for an example.

STATUS
======

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

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

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

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

2. On the Project menu, click References, and then select the Microsoft
   Excel 8.0 object library.

3. Place an OLE control on Form1 and create a new Microsoft Excel
   worksheet. The OLE control properties should be:

      Property    Value
      -----------------

      Name        OLE1

      Class       Excel.Sheet.8

4. Place a CommandButton on Form1.

5. Copy the following code to the Code Window of Form1:

      Private Sub Command1_Click()
         Dim xlBook As Excel.Workbook
         Set xlBook = OLE1.object
         OLE1.DoVerb vbOLEShow 'or OLE1.DoVerb vbOLEUIActivate
         xlBook.Worksheets("Sheet1").Range("A1").Value = "Hello"
         xlBook.Worksheets("Sheet1").PrintOut
         Set xlBook = Nothing
      End Sub

6. On the Run menu, click Start, or press the F5 key to start the program.

7. Click the CommandButton. Visual Basic hangs after it encounters the
   PrintOut method. The object will be correctly printed, but Visual Basic
   stops responding. You must select End Task in the task list (by
   pressing the CTRL+ALT+DEL keys) to end the Visual Basic project and
   Excel. Repeat until both Excel and the Visual Basic project are removed
   from the task list.

8. Repeat the steps again with the code modified as follows:

      Private Sub Command1_Click()
         Dim xlBook As Excel.Workbook
         Set xlBook = OLE1.object
         OLE1.DoVerb vbOLEShow 'or OLE1.DoVerb vbOLEUIActivate
         xlBook.Worksheets("Sheet1").Range("A1").Value = "Hello"
         Command1.SetFocus 'causes deactivation of object
         xlBook.Worksheets("Sheet1").PrintOut
         OLE1.DoVerb vbOLEShow 'optional: reactivates object
         Set xlBook = Nothing
      End Sub

The problem is avoided by deactivating the object before calling the
PrintOut method. Setting focus to any control on the form will deactivate
the OLE control object.

Additional query words: locks freezes crashes
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Keywords          : vb5all VBKBAutomation
Technology        : ole
Version           : WINDOWS:5.0,97
Platform          : WINDOWS
Issue type        : kbbug
Solution Type     : kbpending

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

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Copyright Microsoft Corporation 1998.