Question

Technology: C#, Winforms

The Background:
I have the following container structure (Form containing a panel, which contains 2 panels)

Form F1
 |-> Panel P1 (DockStyle.Fill)
        |-> Panel P2 (DockStyle.Top)
        |-> Panel P3 (DockStyle.Fill)

I register for P3.SizeChange event and in the event I change P2.Size

The Problem:
I expect all the size changes will be reflected correctly on the GUI

Observed result:
Every time P2.Size changes based on the previously set Size

What I have tried:

1. I have tried calling PerformLayout and Invalidate, but still the GUI does not correctly reflect the changes.
2. If I hook up the same function to F1.SizeChange, it all works fine
3. Instead of changing the Size, if I change and revert the DockStyle (P3.Dock = DockStyle.None; P3.Dock = DockStyle.Fill), it messes up the GUI

Seems like in Forms library I cannot change a layout related property (Size, Dock, etc) from a sibling control’s layout related event (SizeChanged)

Has anyone else encountered this issue and have a workaround?
I am using .NET 4.0 (I think) from Visual Studio Express 2010

Inputs will be greatly appreciated

Answer 1

Try changing the size in the next message loop iteration (which will happen after the layout pass ends) by doing it in BeginInvoke().