PRB: ActiveX Control Cannot Assign Run-Time Read-Only Property

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

SYMPTOMS

When your Usercontrol attempts to expose a run-time read-only property of a constituent control, you get the following error:

   Compile Error:
   Can't Assign to Read-Only Property

CAUSE

The run-time read-only properties of constituent controls cannot be exposed.

Because properties of the UserControl object and constituent controls are exposed by delegation, you cannot expose design-time-only properties such as Appearance and ClipControls. The settings you choose for such properties will be fixed for your ActiveX control.

STATUS

This behavior is by design.

MORE INFORMATION

Steps to Reproduce Behavior

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

2. Add a text box to UserControl1.

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

         Option Explicit
         Property Let Multiline(b As Boolean)
            Text1.Multiline = b
         End Property
   
         Property Get Multiline() As Boolean
            Multiline = Text1.Multiline
         End Property
   
   

4. Close UserControl1.

5. Add a Standard EXE project to the project group by completing the following steps:

   - From the File Menu, click Add Project. The Add Project dialog box

        displays.
   

   - Click Standard EXE and click Open to close the Add Project dialog box

        and open the Form1 form of the second project.
   

6. Add Usercontrol1 to Form1.

7. In the Properties window for the Usercontrol, attempt to set the MultiLine property to True and note that you receive the compile error described above.

REFERENCES

"Exposing Properties of Constituent Controls", Books Online

Keywords          : vb5all VBKBAX VBKBComp VBKBCtrl kberrmsg
Version           : WINDOWS:5.0
Platform          : WINDOWS
Issue type        : kbprb
Solution Type     : kbwontfix