How to prevent MouseUp event after DoubleClick on Window TitleBar in WPF? - wpf

Question

If user double-clicks window title bar to maximize window, the window will maximize on MouseDown event of the second click, but then the MouseUp event on that same second click will be registered by one of the controls in the window that are now under the cursor and trigger something user didn't want.
How can it be prevented?

Answer 1

This should work just fine:
Solution:
//WNDPROC INTEROP
private const int WM_NCLBUTTONDBLCLK = 0x00A3;
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
source.AddHook(WndProc);
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
//TITLE BAR DOUBLE CLICK
if (msg == WM_NCLBUTTONDBLCLK)
{
Console.WriteLine("titlebar double click " + this.WindowState);
//WINDOW ABOUT TO GET MAXIMIZED
if (msg == WM_NCLBUTTONDBLCLK)
handleNextMouseup = true;
else if (msg == 0x202) // mouseup
{
if (handleNextMouseup)
handled = true;
handleNextMouseup = false;
}
}
return IntPtr.Zero;
}
another possible solution:
//WNDPROC INTEROP
private const int WM_NCLBUTTONDBLCLK = 0x00A3;
protected override void OnSourceInitialized(EventArgs e)
{
base.OnSourceInitialized(e);
HwndSource source = PresentationSource.FromVisual(this) as HwndSource;
source.AddHook(WndProc);
}
private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
{
//TITLE BAR DOUBLE CLICK
if (msg == WM_NCLBUTTONDBLCLK)
{
Console.WriteLine("titlebar double click " + this.WindowState);
//WINDOW ABOUT TO GET MAXIMIZED
if (this.WindowState == WindowState.Normal)
{
fakehittestvisible = true;
}
}
return IntPtr.Zero;
}
private bool fakehittestvisible = false;
//ON PREVIEW MOUSE UP ABORT IF MIXIMIZING HAPPENED
private void this_PreviewMouseUp(object sender, MouseButtonEventArgs e)
{
if (fakehittestvisible)
{
e.Handled = true;
fakehittestvisible = false;
return;
}
fakehittestvisible = false;
Console.WriteLine("this mouse up state is " + this.WindowState);
}