To prevent lots of flicker during resizing disable the real-time resizing of the child controls.
To do so override both the Form OnResizeBegin and OnResizeEnd events.
protected override void OnResizeBegin(EventArgs e)
{
SuspendLayout();
base.OnResizeBegin(e);
}
protected override void OnResizeEnd(EventArgs e)
{
ResumeLayout();
base.OnResizeEnd(e);
}
I have found some interesting solutions for this including iterating all controls and check for their focus state.
The ActiveControl property of the form class also seems to work rather well …
Set a form to “autosize” allows the form to shrink or grow by it’s contents. It however does not allow the user to resize the form manually.
To allow the user to resize the form set the form AutoSize property to false in the form onLoad event handler. This allows the form resize initially but user resizable afterwards.
Of course changing the contents of the hosted controls may require you to resize the form. You can set the AutoSize to true before making the changes or use the GetPreferredSize method and resize the form yourself.
By default forms do not get keyboard input.
To allow keyboard input set the forms KeyPreview property to true.
This will enable the firing of the KeyDown and KeyUp events.