protected override void OnParentChanged(EventArgs e)
{
if (prevParent != null)
{
WndProcHooker.UnhookWndProc(prevParent, WM_LBUTTONDOWN);
WndProcHooker.UnhookWndProc(prevParent, WM_LBUTTONUP);
}
prevParent = Parent;
if (Parent != null)
{
WndProcHooker.HookWndProc(Parent, WM_LBUTTONDOWN_Handler, WM_LBUTTONDOWN);
WndProcHooker.HookWndProc(Parent, WM_LBUTTONUP_Handler, WM_LBUTTONUP);
}
base.OnParentChanged(e);
}
/// <summary>
/// Called when the control's parent is changed. Here we hook into that
/// parent's WndProc and spy on the WM_NOTIFY message. When the parent
/// changes, we unhook the old parent's WndProc and hook into the new one.
/// </summary>
/// <param name="e">The arguments for this event</param>
protected override void OnParentChanged(EventArgs e)
{
// unhook the old parent
if (this.prevParent != null)
{
WndProcHooker.UnhookWndProc(prevParent, WinApi.WM_NOTIFY);
}
// update the previous parent
prevParent = this.Parent;
// hook up the new parent
if (this.Parent != null)
{
WndProcHooker.HookWndProc(this.Parent,
new WndProcHooker.WndProcCallback(this.WM_Notify_Handler),
WinApi.WM_NOTIFY);
}
base.OnParentChanged(e);
}