在 WPF 应用程序中支持 Windows 11 Snap Layout

Question

I want to enable SnapLayout for WPF. Because I use Customized Window, according to the documentation , I have to do it myself

For Win32 apps, make sure you are responding appropriately to WM_NCHITTEST (with a return value of HTMAXBUTTON for the maximize/restore button).

I used the following code

private const int HTMAXBUTTON = 9;

private IntPtr HwndSourceHook(IntPtr hwnd, int msg, IntPtr wparam, IntPtr lparam, ref bool handled)
        {
            switch (msg)
            {
                case InteropValues.WM_NCHITTEST:
                    try
                    {
                        int x = lparam.ToInt32() & 0xffff;
                        int y = lparam.ToInt32() >> 16;
                        var rect = new Rect(_ButtonMax.PointToScreen(new Point()), new Size(_ButtonMax.Width, _ButtonMax.Height));
                        if (rect.Contains(new Point(x, y)))
                        {
                            handled = true;
                        }
                        return new IntPtr(HTMAXBUTTON);
                    }
                    catch (OverflowException)
                    {
                        handled = true;
                    }
                    break;
            }

            return IntPtr.Zero;
        }

SnapLayout is displayed well But the maximize button does not work and if I click on it, a button will be created next to it. How can I solve this problem?

Answer 1

Mark the WM_NCLBUTTONDOWN message as handled. This prevents the classic button from showing.

case InteropValues.WM_NCLBUTTONDOWN:
     handled = true;
     break;

Handle various WM_NC * mouse messages and using SendMessage to send related messages to the Window to mimic "client area" mouse messages with translated POINT values so that WPF can receive them.