FIX: User Control Moves When Width/Height Is Set in Container

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

SYMPTOMS

When using a Frame or a PictureBox as its container at run-time, a user- created ActiveX control will move when its width or height is changed. However, the problem does not occur when a Form is used as the container or when the control is placed in the container at design-time.

CAUSE

UserControl caches the window handle it was activated on. When the size is changed, it tries to figure out its current coordinates within its parent by getting its screen coordinates and then mapping them relative to its parent's screen coordinates. Because its cached parent is no longer its real parent, it calculates the wrong coordinates and moves the control to those wrong coordinates.

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 Studio 97 Service Pack 2.

For more information on the Visual Studio 97 Service Pack 2, please see the following article in the Microsoft Knowledge Base:

Q170365 INFO: Visual Studio 97 Service Packs - What, Where, and Why

Q171554 INFO: Visual Basic 5.0 Fixes in Visual Studio 97 Service Pack 2

MORE INFORMATION

Steps to Reproduce Behavior

1. Create a new ActiveX Control project. UserControl1 is created by default.



2. Set some of UserControl1's properties to the following:

   ScaleMode = 3 - Pixel
   Backcolor = Blue or some color other than gray




3. Close UserControl1. It now appears in the Toolbox.



4. Select Add Project from the File menu and add a Standard EXE. Form1 is created by default.



5. Place the following controls on Form1:

   
         Two CommandButton controls(Command1 and Command2);
         One PictureBox (Picture1);
         One UserControl1(UserControl11) that was just created; 

   NOTE: Make Picture1 large and UserControl11 small so that the undesired behavior is more obvious.



6. Set Picture1's ScaleMode to 3 - Pixel.



7. Insert the following code to Command1's Click event procedure:

   
         Set UserControl11.Container = Picture1
         UserControl11.Top = 0
         UserControl11.Left = 0 




8. Insert the following code to Command2's Click event procedure:

   
         UserControl11.Top = 0
         UserControl11.Left = 0
         UserControl11.Width = UserControl11.Width + 30 




9. Press the F5 key to run the application



10. Click on Command1 first. Usercontrol11 should be placed inside the Picture1.



11. Click on Command2. UserControl11 should increase its width. It also moves in Picture1.

Additional query words:

Keywords : kbVBp500 kbVS97sp2fix kbvbp500sp2fix
Version : 5.0
Platform : WINDOWS
Issue type : kbbug