BUG: UserControl Event Is Not Raised from a Modal Form

• Microsoft Visual Basic Learning, Professional, and Enterprise Editions for Windows, version 5.0

SYMPTOMS

If an event is raised from a UserControl while a modal form is active, the event is not executed.

CAUSE

The event is not executed if the UserControl is compiled into an OCX and referenced from a project that is run in the IDE.

RESOLUTION

There are two workarounds to this problem:

- Use the compiled ActiveX component (OCX) only with compiled client

  programs (EXE). In other words, both Visual Basic projects are compiled.

  -or-

  project group. In other words, both Visual Basic projects are in design
  mode.

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

The following section shows you how to create a sample project that demonstrates this problem. To reproduce this behavior, you first need to create a compiled ActiveX control with a custom event. Then you make a reference to this control from another project and run that project in the IDE.

Create the ActiveX Control

1. Start a new ActiveX control project in Visual Basic. UserControl1 is created by default.

2. Add a new form to the project. Add a CommandButton to Form1.

3. Copy the following code to the Code window of UserControl1:

         Option Explicit
         Public WithEvents MyCommand As CommandButton
         Event TestEvent()
   

         Private Sub Command1_Click()
            Set MyCommand = Form1.Command1
            Form1.Show vbModal
         End Sub
   
         Private Sub MyCommand_Click()
            RaiseEvent TestEvent
         End Sub
   
         Private Sub UserControl_Click()
            Set MyCommand = Form1.Command1
            Form1.Caption = "UserControl Form"
            Form1.Show vbModal
         End Sub
   
   

4. Compile UserControl1 into an OCX file. Close all open windows associated with UserControl1.

Create the Sample Project

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

2. Make a reference to the ActiveX control you created in the previous section by completing the following steps:

       - From the Project menu, click Components. The Components dialog box
         is displayed.
   

       - Click Browse to open a dialog box that allows you to select the
         ActiveX component created in the previous section.
   

       - Click OK to close the dialog boxes.
   

3. Add the ActiveX control to the Form1 form. Adjust the ActiveX control size to take up most of the form.

4. Copy the following code to the Code window of Form1:

         Option Explicit
         Private Sub UserControl11_TestEvent()
            MsgBox "In the User control test event"
         End Sub
   
   

5. Press the F5 key to run the project and click on Form1. The UserControl Form appears. Click Command1 and note that the message box indicating the custom event has executed does not appear.

6. Make the project into an EXE and run the EXE. Click Form1. The

       UserControl Form appears. Click Command1 and note that the message box
       indicating the custom event has executed does appear.