BUG: MDI Child Windows Control Box Affected by Parent Toolbars

• Standard, Professional, and Enterprise Editions of Microsoft Visual Basic, 32-bit only, for Windows, version 4.0

SYMPTOMS

Placing a Windows Common Control's Toolbar on an MDI Parent form affects the functionality of the Control Box on MDI Child windows under Windows NT 3.51. Under normal circumstances, double-clicking a Control Box closes a window as if the user had clicked once to drop down the menu and then selected "Close." When the Toolbar is placed on a Parent window under Windows NT 3.51, double-clicking the Control Box drops the menu but doesn't dismiss the window.

This problem doesn't occur with Visual Basic under Windows NT version 4.0 or Windows 95.

RESOLUTION

If you add a PictureBox control to the Form, and Cut and Paste the Toolbar onto the PictureBox, the problem is resolved. When you run the code after doing this, the Control Box behaves in the expected manner.

MORE INFORMATION

Steps to Reproduce Problem

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

2. Set the MDIChild property of Form1 to TRUE.

3. From the Insert menu, choose MDI Form.

4. Add a Toolbar Control to the MDI Form. No images or buttons are required to show the problem.

5. Press the F5 key to start the project.

6. Maximize the Child Window.

7. Double-click the Control Box of the Child Window. The menu should drop down, but the window is not dismissed.

STATUS

Microsoft has confirmed this to be a bug in the Microsoft products listed at the beginning of this article. We are researching this problem and will post new information here in the Microsoft Knowledge Base as it becomes available.

REFERENCES