Q159410: FIX: "Invalid Procedure Call" Referencing Collection Item

Article: Q159410
Product(s): Microsoft Visual Basic for Windows
Version(s): 
Operating System(s): 
Keyword(s): kbGrpDSVB
Last Modified: 11-JAN-2001

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The information in this article applies to:

- Microsoft Visual Basic Standard Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Professional Edition, 32-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 16-bit, for Windows, version 4.0 
- Microsoft Visual Basic Enterprise Edition, 32-bit, for Windows, version 4.0 
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SYMPTOMS
========

If you reference a collection object created by an out-of-process OLE server
with a variable index and the index variable is specified as an Integer or Long
in a Dimension statement, the following error appears:

  "Invalid Procedure Call"

RESOLUTION
==========

Make sure that the index variable is specified as Variant in the Dimension
statement.

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 Basic 6.0.

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

The out-of-process OLE server (EXE server) that created the collection object
receives the index through remote procedure call (RPC). This data is marshaled
across the processes and received as a Variant data type only.

This behavior does not occur if the collection object is created in an in-process
server because RPC is in the same process and is not needed to transmit the data
between the two different processes.

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

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

2. On the Visual Basic menu, click Insert and Class Module to add a new class
  module.

3. Insert the following code into the class module code window:

     Dim x As New Collection

     Public Function PassCollection() As Collection
              x.Add "Item 1"
              x.Add "Item 2"
              x.Add "Item 3"

              Set PassCollection = x
     End Function

4. Change the following properties on the class module:

     Instancing = 2-Createable MultiUse
     Public = True

5. On the Visual Basic menu, click Insert and Module to add a new Basic code
  module.

6. Insert the following code in the code window of the Basic code module:

     Sub main()
              Load Form1
     End Sub

7. On the Visual Basic menu, click Tools and Options. On the Project tab, change
  the following fields:

  Startup Form = Sub Main
  Project Name = OLECOL
  StartMode = OLE Server
  Application Description = OLE Collection Example

8. Click OK, and then press the F5 key to run the project.

9. Start another session of Visual Basic. A new Project with Form1 appears by
  default.

10. Place a CommandButton on Form1.

11. Insert the following code into the General Declaration section of the code
  window for Form1:

      Private Sub Command1_Click()
               Dim c As Collection
               Dim o As New OLECOL.Class1
               Dim i As Long

               Set c = o.PassCollection

               For i = 1 To c.Count
      MsgBox c(i)
               Next i
      End Sub

12. On the Visual Basic menu, click Tools and References. Select "OLE Collection
  Example" on the reference list, and then click OK.

13. Run the project by pressing the F5 key and clicking on Command1. The
  following error message appears:

  "Invalid Procedure Call"

Additional query words: kbVBp400bug kbVBp600fix kbVBp kbdsd kbDSupport kbVBA

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Keywords          : kbGrpDSVB 
Technology        : kbVBSearch kbAudDeveloper kbVB400Search kbVB400 kbVB16bitSearch
Issue type        : kbbug kbprb
Solution Type     : kbfix

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

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