imports three functions to display the vertical and horizontal size of the screen.
using System; using System.Runtime.InteropServices; public class Starter { public static void Main() { IntPtr hDC = API.GetDC(IntPtr.Zero); int v = API.GetDeviceCaps(hDC, API.HORZRES); Console.WriteLine("Vertical size of window {0}mm.", v); int h = API.GetDeviceCaps(hDC, API.HORZRES); Console.WriteLine("Horizontal size of window {0}mm.", h); int resp = API.ReleaseDC(IntPtr.Zero, hDC); if (resp != 1) { Console.WriteLine("Error releasing hdc"); } } } public static class API { [DllImport("user32.dll")] public static extern IntPtr GetDC(IntPtr hWnd); [DllImport("user32.dll")] public static extern int ReleaseDC(IntPtr hWnd, IntPtr hDC); [DllImport("gdi32.dll")] public static extern int GetDeviceCaps(IntPtr hDC, int nIndex); public const int HORZSIZE = 4; // horizontal size in pixels public const int VERTSIZE = 6; // vertical size in pixels public const int HORZRES = 8; // horizontal size in millimeters public const int VERTRES = 10; // vertical size in millimeters }