Knowledge Base

BUG: Type Mismatch Referencing UserControl on Unloaded Form

Article ID: 187633

Article Last Modified on 5/13/2003

Microsoft Visual Basic 5.0 Learning Edition
Microsoft Visual Basic 6.0 Learning Edition
Microsoft Visual Basic 5.0 Professional Edition
Microsoft Visual Basic 6.0 Professional Edition
Microsoft Visual Basic 5.0 Enterprise Edition
Microsoft Visual Basic 6.0 Enterprise Edition

This article was previously published under Q187633

SYMPTOMS

If you attempt to set an object variable referencing a UserControl on an unloaded form, and the UserControl resides in the same project as the Module containing the declaration, a TypeMismatch error occurs. This problem does not occur if the form is loaded, if the UserControl is in a different project, or if the code is placed in the Load Event of the Form containing the UserControl.

RESOLUTION

Load the Form before referencing the UserControl. For example:

      Sub Main()
         Load Form1
         Dim ctlMyControl as UserControl1
         Set ctlMyControl = Form1.UserControl11
      End Sub

Place the UserControl in a different project. -or-
Move the code to the Load Event of the Form containing the UserControl.

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

Start a new Standard EXE project in Visual Basic. Form1 is created by default.
From the Project menu, add a UserControl to the project.
Close the UserControl window, and add the UserControl to Form1.
From the Project menu, add a Module to the project.

Insert the following code into Module1:

      Sub Main()
         Dim ctlMyControl as UserControl1
         Set ctlMyControl = Form1.UserControl1
      End Sub

From the Project menu, chose Project1 Properties, and change the Startup Object to SubMain.
Run the project, and note that you receive the "Type Mismatch" error at this point.

Additional query words: kbDSupport kbDSD kbVBp500Bug kbNoKeyWord kbVBp600bug

Keywords: kbbug KB187633