C# 为程序设置全局热键/Hotkey

首先我们需要定义一个Hotkey（热键）类，我推荐大家通过新建一个类文件来存放代码，方便以后调用,例如我的类文件代码如下

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Text;
using System.Windows.Forms;
using System.Runtime.InteropServices;
using System.Collections;

namespace Windows
{
public delegate void HotkeyEventHandler(int HotKeyID);

public class Hotkey : System.Windows.Forms.IMessageFilter
{
    Hashtable keyIDs = new Hashtable();
    IntPtr hWnd;
     
    static public int Hotkey1;

    public event HotkeyEventHandler OnHotkey;

    public enum KeyFlags
    {  
        MOD_NONE= 0x0,
        MOD_ALT = 0x1,
        MOD_CONTROL = 0x2,
        MOD_SHIFT = 0x4,
        MOD_WIN = 0x8
    }
    [DllImport("user32.dll")]
    public static extern UInt32 RegisterHotKey(IntPtr hWnd, UInt32 id, UInt32 fsModifiers, UInt32 vk);

    [DllImport("user32.dll")]
    public static extern UInt32 UnregisterHotKey(IntPtr hWnd, UInt32 id);

    [DllImport("kernel32.dll")]
    public static extern UInt32 GlobalAddAtom(String lpString);

    [DllImport("kernel32.dll")]
    public static extern UInt32 GlobalDeleteAtom(UInt32 nAtom);

    public Hotkey(IntPtr hWnd)
    {
        this.hWnd = hWnd;
        Application.AddMessageFilter(this);
    }

    public int RegisterHotkey(Keys Key, KeyFlags keyflags)
    {
        UInt32 hotkeyid = GlobalAddAtom(System.Guid.NewGuid().ToString());
        RegisterHotKey((IntPtr)hWnd, hotkeyid, (UInt32)keyflags, (UInt32)Key);
        keyIDs.Add(hotkeyid, hotkeyid);
        return (int)hotkeyid;
    }

    public void UnregisterHotkeys()
    {
        Application.RemoveMessageFilter(this);
        foreach (UInt32 key in keyIDs.Values)
        {
            UnregisterHotKey(hWnd, key);
            GlobalDeleteAtom(key);
        }
    }

    public bool PreFilterMessage(ref System.Windows.Forms.Message m)
    {
        if (m.Msg == 0x312)
        {
            if (OnHotkey != null)
            {
                foreach (UInt32 key in keyIDs.Values)
                {
                    if ((UInt32)m.WParam == key)
                    {
                        OnHotkey((int)m.WParam);
                        return true;
                    }
                }
            }
        }
        return false;
    }
}

}

接着我们要定义一个方法，用来设置热键的行为，例如我设置热键打开/隐藏程序界面。

public void OnHotkey(int HotkeyID) //设置热键的行为
{
if (HotkeyID == Hotkey.Hotkey1)
{
if (this.Visible == true)
this.Visible = false;
else
this.Visible = true;
}
else
{
this.Visible = false;
}
}

最后在窗体的load事件加入下面的代码就成功了。

private void Form1_Load(object sender, EventArgs e)
{
Hotkey hotkey;
hotkey = new Hotkey(this.Handle);
Hotkey.Hotkey1 = hotkey.RegisterHotkey(System.Windows.Forms.Keys.F3, Hotkey.KeyFlags.MOD_ALT); //定义快键(Alt + F3) ,如果是hotkey.RegisterHotkey(System.Windows.Forms.Keys.F3, Hotkey.KeyFlags.MOD_NONE);//只注册F3
hotkey.OnHotkey += new HotkeyEventHandler(OnHotkey);
}