protected override IntPtr WndProcOverride(HWND hwnd, WM msg, IntPtr wParam, IntPtr lParam, IntPtr id, IntPtr data)
{
IntPtr? result = null;
if (msg == WM.WINDOWPOSCHANGING) {
unsafe
{
WINDOWPOS* pWindowPos = (WINDOWPOS*)lParam;
CopyBitsBehavior copyBitsBehavior = _hwndHost.GetCopyBitsBehavior();
switch (copyBitsBehavior) {
case CopyBitsBehavior.AlwaysCopyBits:
pWindowPos->flags &= ~SWP.NOCOPYBITS;
break;
case CopyBitsBehavior.CopyBitsAndRepaint:
pWindowPos->flags &= ~SWP.NOCOPYBITS;
if (!_redrawMessagePosted) {
NativeMethods.PostMessage(hwnd, _redrawMessage, IntPtr.Zero, IntPtr.Zero);
_redrawMessagePosted = true;
}
break;
case CopyBitsBehavior.NeverCopyBits:
pWindowPos->flags |= SWP.NOCOPYBITS;
break;
case CopyBitsBehavior.Default:
default:
// do nothing.
break;
}
}
} else if (msg == _redrawMessage) {
_redrawMessagePosted = false;
// Invalidate the window that moved, because it might have copied garbage
// due to WPF rendering through DX on a different thread.
NativeMethods.RedrawWindow(hwnd, IntPtr.Zero, IntPtr.Zero, RDW.INVALIDATE | RDW.ALLCHILDREN);
// Then immediately redraw all invalid regions within the top-level window.
HWND hwndRoot = NativeMethods.GetAncestor(hwnd, GA.ROOT);
NativeMethods.RedrawWindow(hwndRoot, IntPtr.Zero, IntPtr.Zero, RDW.UPDATENOW | RDW.ALLCHILDREN);
} else if (msg == WM.MOUSEACTIVATE) {
bool raiseMouseActivateCommand = _hwndHost.GetRaiseMouseActivateCommand();
if (raiseMouseActivateCommand) {
// Raise the HwndHostCommands.MouseActivate command.
MouseActivateParameter parameter = new MouseActivateParameter();
HwndHostCommands.MouseActivate.Execute(parameter, _hwndHost);
if (parameter.HandleMessage) {
if (parameter.Activate == false && parameter.EatMessage == false) {
result = new IntPtr((int)MA.NOACTIVATE);
} else if (parameter.Activate == false && parameter.EatMessage == true) {
result = new IntPtr((int)MA.NOACTIVATEANDEAT);
} else if (parameter.Activate == true && parameter.EatMessage == false) {
result = new IntPtr((int)MA.ACTIVATE);
} else // if(parameter.Activate == true && parameter.EatMessage == true)
{
result = new IntPtr((int)MA.ACTIVATEANDEAT);
}
}
}
}
return result ?? base.WndProcOverride(hwnd, msg, wParam, lParam, id, data);
}
