C#系统热键类

C#系统热键类

using System;
using System.Runtime.InteropServices;

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

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

        public event HotkeyEventHandler OnHotkey;

        public enum KeyFlags
        {
            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;
            System.Windows.Forms.Application.AddMessageFilter(this);
        }

        public int RegisterHotkey(System.Windows.Forms.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()
        {
            System.Windows.Forms.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;
        }
    }
}

该类的使用方法：

在窗体的类中声明一个变量

private int Hotkey1

在窗体的Load事件中加入如下代码

Hotkey hotkey;
hotkey = new Hotkey(this.Handle);
Hotkey1 = hotkey.RegisterHotkey(System.Windows.Forms.Keys.F1, Hotkey.KeyFlags.MOD_CONTROL);//定义快键(Ctrl + F1)
hotkey.OnHotkey += new HotkeyEventHandler(OnHotkey);

添加快键调用函数

public void OnHotkey(int HotkeyID)
{
    if(HotkeyID == Hotkey1)
    {
        if(this.Visible == true)
            this.Visible = false;
        else
            this.Visible = true;
    }
    else
    {
        this.Visible = false;
    }
}