private static void WmGetMinMaxInfo(IntPtr hwnd, IntPtr lParam) { SafeNativeMethods.MINMAXINFO mmi = (SafeNativeMethods.MINMAXINFO)Marshal.PtrToStructure(lParam, typeof(SafeNativeMethods.MINMAXINFO)); // Adjust the maximized size and position to fit the work area of the correct monitor int MONITOR_DEFAULTTONEAREST = 0x00000002; IntPtr monitor = SafeNativeMethods.MonitorFromWindow(hwnd, MONITOR_DEFAULTTONEAREST); if (monitor != IntPtr.Zero) { SafeNativeMethods.MONITORINFO monitorInfo = new SafeNativeMethods.MONITORINFO(); SafeNativeMethods.GetMonitorInfo(monitor, monitorInfo); SafeNativeMethods.RECT rcWorkArea = monitorInfo.rcWork; SafeNativeMethods.RECT 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); }