Shutdown -> WM_QUERYENDSESSION in WPF-Project

With WinForms it is easy:

but how to do it in WPF, what is the place for WndProc

namespace WinFormsApp1
{
    public partial class Form1 : Form
    {
        private static int WM_QUERYENDSESSION = 0x11;
        public Form2()
        {
            InitializeComponent();
        }
        protected override void WndProc(ref Message m)
        {
            if (m.Msg == WM_QUERYENDSESSION)
            {
                MessageBox.Show("logoff, shutdown, or reboot");
            }
            base.WndProc(ref m);
        }
    }
}

Code Snippet

public partial class MainWindow : Window
{
    private const int WM_CLOSE = 0x0010;

    public MainWindow()
    {
        InitializeComponent();
    }

    protected override void OnSourceInitialized(EventArgs e)
    {
        base.OnSourceInitialized(e);
        WindowInteropHelper wih = new WindowInteropHelper(this);
        HwndSource source = HwndSource.FromHwnd(wih.Handle);
        source.AddHook(new HwndSourceHook(WndProc));
    }

    private IntPtr WndProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, ref bool handled)
    {
        switch (msg)
        {
            case WM_CLOSE:
                MessageBox.Show("Bye!");
                break;
            default:
                break;
        }
        return IntPtr.Zero;
    }
}

Except you might need to do something different for the return value, it has been a few years since I did any of that. I leave that for you to find.