C means to control the switch of the display by hotkeys

This article illustrates how C# controls the switch of the display by hotkeys. Share to everybody for everybody reference.

Specific implementation methods are as follows:

using System;

using System.Collections.Generic;

using System.ComponentModel;

using System.Data;

using System.Drawing;

using System.Linq;

using System.Text;

using System.Windows.Forms;

using System.Runtime.InteropServices;
namespace OpenMonitor

{

    public partial class Form1 : Form

    {

        public Form1()

        {

            InitializeComponent();

            HotKey.RegisterHotKey(this.Handle, 100, 0, Keys.F4);

            HotKey.RegisterHotKey(this.Handle,101,0,Keys.F5);

        }
        class HotKey

        {

            //  If the function executes successfully, the return value is not 0 .  

            //  If the function fails, the return value is 0 . To get the extension error message, call GetLastError .  

            [DllImport("user32.dll  ", SetLastError = true)]

            public static extern bool RegisterHotKey(

                   IntPtr hWnd, //  Handle to the window to define the hotkey  

                    int id,    //  Define hotkeys ID (Not with others ID Repeated)    

                   KeyModifiers fsModifiers, //  Identifies whether the hotkey is being pressed Alt , Ctrl , Shift , Windows It doesn't take effect until you wait for the key  

                   Keys vk    //  Define the contents of the hotkey  

                   );
            [DllImport("user32.dll  ", SetLastError = true)]

            public static extern bool UnregisterHotKey(

                   IntPtr hWnd,  //  Handle to the window to cancel the hotkey  

                    int id      //  You want to cancel hotkeys ID 

                   );
            //  Defines the name of the secondary key (converts a number to a character for memorization, or uses a numeric value instead of an enumeration)  

            [Flags()]

            public enum KeyModifiers

            {

                None = 0,

                Alt = 1,

                Ctrl = 2,

                Shift = 4,

                WindowsKey = 8

            }

        }
        protected override void WndProc(ref    Message m)

        {

            const int WM_HOTKEY = 0x0312;

            //  According to the shortcut key    

            switch (m.Msg)

            {

                case WM_HOTKEY:

                    switch (m.WParam.ToInt32())

                    {

                        case 100:

                            MonitorHelper.TurnOn();

                            break;

                        case 101:

                            MonitorHelper.TurnOff();

                            break;

                    }

                    break;

            }

            base.WndProc(ref    m);

        }
        class MonitorHelper

        {

            public static void TurnOn()

            {

                SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, -1);

            }
            public static void TurnOff()

            {

                SendMessage(HWND_BROADCAST, WM_SYSCOMMAND, SC_MONITORPOWER, 2);

            }
            [DllImport("user32.dll")]

            public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, int lParam);
            private static readonly IntPtr HWND_BROADCAST = new IntPtr(0xffff);

            private const uint WM_SYSCOMMAND = 0x0112;

            private const int SC_MONITORPOWER = 0xf170;

        }

    }

}

Hopefully this article has helped you with your C# programming.