WPF之1：注册热键

最近做一个自动截图工具(用WPF)，其中用到了热键的一点知识，参照了网上前辈们得经验，

总结如下：

using System;
using System.Collections.Generic;
using System.Text;

// new add
using System.Windows;
using System.Windows.Forms;
using System.Collections;
using System.Windows.Interop;

namespace RegisterHotKey
{
    ///<summary>    
    /// 直接构造类实例即可注册
    /// 自动完成注销
    /// 注意注册时会抛出异常
    /// 注册系统热键类
    /// 热键会随着程序结束自动解除,不会写入注册表
    ///</summary>
publicclass HotKey
    {
        #region Member

        int KeyId;         //热键编号
        IntPtr Handle ;     //窗体句柄
        Window Window ;     //热键所在窗体
uint ControlKey ;   //热键控制键
uint Key ;          //热键主键

        publicdelegatevoid OnHotKeyEventHandler();     //热键事件委托
publicevent OnHotKeyEventHandler OnHotKey =null;   //热键事件

        static Hashtable KeyPair =new Hashtable();         //热键哈希表
privateconstint WM_HOTKEY =0x0312;       // 热键消息编号

        publicenum KeyFlags    //控制键编码        
        {            
            MOD_ALT =0x1,
            MOD_CONTROL =0x2,
            MOD_SHIFT =0x4,
            MOD_WIN =0x8
        }  

        #endregion

        ///<summary>
        /// 构造函数
        ///</summary>
        ///<param name="win">注册窗体</param>
        ///<param name="control">控制键</param>
        ///<param name="key">主键</param>
public HotKey(Window win, HotKey.KeyFlags control, Keys key)
        {
            Handle =new WindowInteropHelper(win).Handle;
            Window = win;
            ControlKey = (uint)control;
            Key = (uint)key;
            KeyId = (int)ControlKey + (int)Key *10;

            if (HotKey.KeyPair.ContainsKey(KeyId))
            {
                thrownew Exception("热键已经被注册!");
            }

            //注册热键
if (false== HotKey.RegisterHotKey(Handle, KeyId, ControlKey, Key)) 
            {
                thrownew Exception("热键注册失败!");
            }

            //消息挂钩只能连接一次!!
if(HotKey.KeyPair.Count==0)
            {
                if (false== InstallHotKeyHook(this))
                {
                    thrownew Exception("消息挂钩连接失败!");
                }
            }

            //添加这个热键索引
            HotKey.KeyPair.Add(KeyId, this);
        }

        //析构函数,解除热键
~HotKey()
        {
            HotKey.UnregisterHotKey(Handle, KeyId);
        }

        #region core

        [System.Runtime.InteropServices.DllImport("user32")]
        privatestaticexternbool RegisterHotKey(IntPtr hWnd, int id, uint controlKey, uint virtualKey);

        [System.Runtime.InteropServices.DllImport("user32")]
        privatestaticexternbool UnregisterHotKey(IntPtr hWnd, int id);

        //安装热键处理挂钩
staticprivatebool InstallHotKeyHook(HotKey hk)
        {
            if (hk.Window ==null|| hk.Handle == IntPtr.Zero)
            {
                returnfalse;
            }

            //获得消息源
            System.Windows.Interop.HwndSource source = System.Windows.Interop.HwndSource.FromHwnd(hk.Handle);
            if (source ==null)
            {
                returnfalse;
            }

            //挂接事件            
            source.AddHook(HotKey.HotKeyHook);            
            returntrue;
        }

        //热键处理过程
staticprivate IntPtr HotKeyHook(IntPtr hwnd, int msg, IntPtr wParam, IntPtr lParam, refbool handled)
        {
            if (msg == WM_HOTKEY) 
            { 
                HotKey hk = (HotKey)HotKey.KeyPair[(int)wParam];
                if (hk.OnHotKey !=null)
                {
                    hk.OnHotKey();
                }
            } 
            return IntPtr.Zero;
        }

        #endregion
    }
}

最后需要注意的是，在应用这个HotKey的时候，不能用在window的构造函数内， 需要放到loaded 事件里，因为要等到window构造完成才能够挂载系统热键，如下：

privatevoid Window_Loaded(object sender, RoutedEventArgs e)
        {
            HotKey hotKey =new HotKey(this, HotKey.KeyFlags.MOD_CONTROL | HotKey.KeyFlags.MOD_SHIFT, System.Windows.Forms.Keys.F12);
            hotKey.OnHotKey +=new HotKey.OnHotKeyEventHandler(hotKey_OnHotKey);
        }

        privatevoid hotKey_OnHotKey()
        {
            if (this.WindowState == WindowState.Normal)
            {
                this.WindowState = WindowState.Minimized;
                this.Hide();
            }
            else
            {
                this.Show();
                this.WindowState = WindowState.Normal;
            }
        }

 

本文参考地址：http://www.cnblogs.com/dabaopku/archive/2010/02/21/1670793.html