BUG: VB Hangs While Automating Excel Using OLE Control

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. For Excel 2000, select the version 9.0 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.