c#如何控制显示器开关？c#实现热键控制显示器的方法

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
{
// 如果函数执行成功，返回值不为0。
// 如果函数执行失败，返回值为0。要得到扩展错误信息，调用GetLastError。
[DllImport("user32.dll  ", SetLastError = true)]
public static extern bool RegisterHotKey(
   IntPtr hWnd, // 要定义热键的窗口的句柄
int id,// 定义热键ID（不能与其它ID重复）  
   KeyModifiers fsModifiers, // 标识热键是否在按Alt、Ctrl、Shift、Windows等键时才会生效
   Keys vk// 定义热键的内容
   );
[DllImport("user32.dll  ", SetLastError = true)]
public static extern bool UnregisterHotKey(
   IntPtr hWnd,  // 要取消热键的窗口的句柄
int id  // 要取消热键的ID
   );
// 定义了辅助键的名称（将数字转变为字符以便于记忆，也可去除此枚举而直接使用数值）
[Flags()]
public enum KeyModifiers
{
None = 0,
Alt = 1,
Ctrl = 2,
Shift = 4,
WindowsKey = 8
}
}
protected override void WndProc(refMessage m)
{
const int WM_HOTKEY = 0x0312;
// 按快捷键  
switch (m.Msg)
{
case WM_HOTKEY:
switch (m.WParam.ToInt32())
{
case 100:
MonitorHelper.TurnOn();
break;
case 101:
MonitorHelper.TurnOff();
break;
}
break;
}
base.WndProc(refm);
}
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;
}
}
}