PRB: Resizing OCX Does Not Resize Its Component Control(s)

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

SYMPTOMS

When resizing your ActiveX control on a host form, the component controls or user-drawn graphics do not get resized.

CAUSE

You do not have logic in the Resize event of the UserControl object to resize the component control(s) to the new size, or in the Paint event of the UserControl object to redraw the user-drawn graphics.

RESOLUTION

Add code to the UserControl's Resize and/or paint event to resize the component control(s) and user-drawn graphics.

STATUS

This is behavior is by design.

MORE INFORMATION

Even though you may want to have various effects when the developer resizes your ActiveX control, Visual Basic has no way of determining how to handle resize issues of your component controls. You can place code in the UserControl_Resize event to handle the resizing in whatever manner you wish.

If your control has no component controls, the UserControl_Paint event allows you to redraw the user-drawn graphics.

Several examples are included below. All code is in the UserControl object.

Resizing a Single Control

The control is resized to fill the entire UserControl by using the following code:

      Private Sub UserControl_Resize()
        Text1.Move 0, 0 , ScaleWidth, ScaleHeight
      End Sub

Resizing a Control and a Label Side-by-Side

The label occupies the leftmost 20% of the user control. The textbox occupies the rightmost 75% of the user control. A 5% gap exists between them, as shown here:

      Private Sub UserControl_Resize()
        Label1.Move 0, 0 , ScaleWidth * .2, ScaleHeight
        Text1.Move ScaleWidth * .25, 0, ScaleWidth * .75, ScaleHeight
      End Sub

Resizing a Shape Control with a Label Drawn Part-Way Down

The shape control fills the entire UserControl. The label occupies the full width and is drawn slightly above center as shown here:

      Private Sub UserControl_Resize()
        Shape1.Move 0, 0 , ScaleWidth, ScaleHeight
        Label1.Move 0, (ScaleHeight - Label1.Height) * .4, ScaleWidth
      End Sub

      Label1.Move 0, ScaleHeight * .28, ScaleWidth, ScaleHeight * .3

      (ScaleHeight - ScaleHeight * .3) * .4
      (ScaleHeight * .7) * .4
      ScaleHeight * .28

Resizing User-Drawn Graphics

The code draws a border around the UserControl and puts an 'X' in it. The ScaleMode needs to be in pixels for the border to paint correctly:

      Private Sub UserControl_Paint()
        UserControl.ScaleMode = vbPixels
        UserControl.Line (0, 0)-(ScaleWidth - 1, ScaleHeight - 1), 0, B
        UserControl.Line (0, 0)-(ScaleWidth - 1, ScaleHeight - 1), 0
        UserControl.Line (0, ScaleHeight - 1)-(ScaleWidth - 1, 0), 0
      End Sub

REFERENCES