UnsafeNativeMethods.cs

#pragma warning disable IDE1006 // Disable naming convention for lowercase variables in methods due to native code interop
namespace ServiceControl.Config.Xaml.Native
{
    using System;
    using System.Runtime.InteropServices;

    static class UnsafeNativeMethods
    {
        [DllImport("dwmapi.dll")]
        public static extern int DwmExtendFrameIntoClientArea(IntPtr hWnd, ref MARGINS pMarInset);

        [DllImport("user32")]
        public static extern bool GetMonitorInfo(IntPtr hMonitor, MONITORINFO lpmi);

        [DllImport("User32")]
        public static extern IntPtr MonitorFromWindow(IntPtr handle, int flags);

        public static void WmGetMinMaxInfo(IntPtr hwnd, IntPtr lParam)
        {
            var mmi = (MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(MINMAXINFO));

            // Adjust the maximized size and position to fit the work area of the correct monitor
            var MONITOR_DEFAULTTONEAREST = 0x00000002;
            var monitor = MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST);

            if (monitor != IntPtr.Zero)
            {
                var monitorInfo = new MONITORINFO();
                GetMonitorInfo(monitor, monitorInfo);
                var rcWorkArea = monitorInfo.rcWork;
                var rcMonitorArea = monitorInfo.rcMonitor;
                mmi.ptMaxPosition.x = Math.Abs(rcWorkArea.left - rcMonitorArea.left);
                mmi.ptMaxPosition.y = Math.Abs(rcWorkArea.top - rcMonitorArea.top);
                mmi.ptMaxSize.x = Math.Abs(rcWorkArea.right - rcWorkArea.left);
                mmi.ptMaxSize.y = Math.Abs(rcWorkArea.bottom - rcWorkArea.top);
            }

            Marshal.StructureToPtr(mmi, lParam, true);
        }

        [DllImport("user32.dll")]
        public static extern IntPtr DefWindowProc(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam);

        [DllImport("user32.dll")]
        public static extern bool ShowWindow(IntPtr hWnd, ShowWindowCommands nCmdShow);
    }
}