键盘"全局钩子"的使用 ..

1. /// <summary>
2.     ///键盘钩子
3.     /// </summary>
4.     public class KeyboardHook  {
5.         
6.         public event KeyEventHandler KeyDownEvent;
7.         public event KeyPressEventHandler KeyPressEvent;
8.         public event KeyEventHandler KeyUpEvent;
10.         public delegate int HookProc(int nCode, Int32 wParam, IntPtr lParam);
13.         static int hKeyboardHook = 0; //声明键盘钩子处理的初始值。
15.         //值在Microsoft SDK的Winuser.h里查询
16.         public const int WH_KEYBOARD_LL = 13;    //线程键盘钩子监听鼠标消息设为2，全局键盘监听鼠标消息设为13。    
18.         HookProc KeyboardHookProcedure; //声明KeyboardHookProcedure作为HookProc类型。
19.             
22.         //键盘结构 
23.         [StructLayout(LayoutKind.Sequential)]
24.         public class KeyboardHookStruct
25.         {
26.             public int vkCode;    //定一个虚拟键码。该代码必须有一个价值的范围1至254 。 
27.             public int scanCode; // 指定的硬件扫描码的关键。 
28.             public int flags;  // 键标志
29.             public int time; // 指定的时间戳记的这个讯息。
30.             public int dwExtraInfo; // 指定额外信息相关的信息。
31.         }
34.         //使用此功能，安装了一个钩子。
35.         [DllImport("user32.dll",CharSet=CharSet.Auto,
36.             CallingConvention=CallingConvention.StdCall)]
37.         public static extern int SetWindowsHookEx(int idHook, HookProc lpfn, 
38.                                                   IntPtr hInstance, int threadId);
41.         //调用此函数卸载钩子。
42.         [DllImport("user32.dll",CharSet=CharSet.Auto,
43.             CallingConvention=CallingConvention.StdCall)]
44.         public static extern bool UnhookWindowsHookEx(int idHook);
47.         //使用此功能，通过信息钩子继续下一个钩子
48.         [DllImport("user32.dll",CharSet=CharSet.Auto,
49.             CallingConvention=CallingConvention.StdCall)]
50.         public static extern int CallNextHookEx(int idHook, int nCode, 
51.                                                 Int32 wParam, IntPtr lParam);
52.         
53.         // 取得当前线程编号（线程钩子需要用到） 
54.         [DllImport("kernel32.dll")]
55.         static extern int GetCurrentThreadId(); 
58.         public void Start()
59.         {
60.             // 安装键盘钩子
61.             if(hKeyboardHook == 0)
62.             {
63.                 KeyboardHookProcedure = new HookProc(KeyboardHookProc);
64.                 hKeyboardHook = SetWindowsHookEx( WH_KEYBOARD_LL,KeyboardHookProcedure, Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]),0);
65.                 //************************************ 
66.                 //键盘线程钩子 
67.                 //SetWindowsHookEx( 2,KeyboardHookProcedure, IntPtr.Zero, GetCurrentThreadId());//指定要监听的线程idGetCurrentThreadId(),
68.                 //键盘全局钩子,需要引用空间(using System.Reflection;) 
69.                 //SetWindowsHookEx( 13,MouseHookProcedure,Marshal.GetHINSTANCE(Assembly.GetExecutingAssembly().GetModules()[0]),0); 
70.                 // 
71.                 //关于SetWindowsHookEx (int idHook, HookProc lpfn, IntPtr hInstance, int threadId)函数将钩子加入到钩子链表中，说明一下四个参数： 
72.                 //idHook 钩子类型，即确定钩子监听何种消息，上面的代码中设为2，即监听键盘消息并且是线程钩子，如果是全局钩子监听键盘消息应设为13， 
73.                 //线程钩子监听鼠标消息设为7，全局钩子监听鼠标消息设为14。lpfn 钩子子程的地址指针。如果dwThreadId参数为0 或是一个由别的进程创建的 
74.                 //线程的标识，lpfn必须指向DLL中的钩子子程。 除此以外，lpfn可以指向当前进程的一段钩子子程代码。钩子函数的入口地址，当钩子钩到任何 
75.                 //消息后便调用这个函数。hInstance应用程序实例的句柄。标识包含lpfn所指的子程的DLL。如果threadId 标识当前进程创建的一个线程，而且子 
76.                 //程代码位于当前进程，hInstance必须为NULL。可以很简单的设定其为本应用程序的实例句柄。threaded 与安装的钩子子程相关联的线程的标识符。 
77.                 //如果为0，钩子子程与所有的线程关联，即为全局钩子。 
78.                 //************************************ 
81.                 //如果SetWindowsHookEx失败。
82.                 if(hKeyboardHook == 0 )    {
83.                     Stop();
84.                     throw new Exception("安装键盘钩子失败");
85.                 }
86.             }
87.         }
89.         public void Stop()
90.         {
91.             bool retKeyboard = true;
92.     
93.             
94.             if(hKeyboardHook != 0)
95.             {
96.                 retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
97.                 hKeyboardHook = 0;
98.             } 
99.             
100.             if (!(retKeyboard)) throw new Exception("卸载钩子失败！");
101.         }
105.         //ToAscii职能的转换指定的虚拟键码和键盘状态的相应字符或字符。
106.         [DllImport("user32")]
107.         public static extern int ToAscii(int uVirtKey, //[in] 指定虚拟关键代码进行翻译。 
108.                                          int uScanCode, // [in] 指定的硬件扫描码的关键须翻译成英文。高阶位的这个值设定的关键，如果是（不压） 。
109.                                          byte[] lpbKeyState, // [in] 指针，以256字节数组，包含当前键盘的状态。每个元素（字节）的数组包含状态的一个关键。如果高阶位的字节是一套，关键是下跌（按下）。在低比特，如果设置表明，关键是对切换。在此功能，只有肘位的CAPS LOCK键是相关的。在切换状态的NUM个锁和滚动锁定键被忽略。
110.                                          byte[] lpwTransKey, // [out] 指针的缓冲区收到翻译字符或字符。 
111.                                          int fuState); // [in] Specifies whether a menu is active. This parameter must be 1 if a menu is active, or 0 otherwise. 
113.         //获取按键的状态
114.         [DllImport("user32")] 
115.         public static extern int GetKeyboardState(byte[] pbKeyState);
117.         private const int WM_KEYDOWN = 0x100;//KEYDOWN 
118.         private const int WM_KEYUP = 0x101;//KEYUP
119.         private const int WM_SYSKEYDOWN = 0x104;//SYSKEYDOWN
120.         private const int WM_SYSKEYUP = 0x105;//SYSKEYUP
122.         private int KeyboardHookProc(int nCode, Int32 wParam, IntPtr lParam)
123.         {
124.             // 侦听键盘事件
125.             if ((nCode >= 0) && (KeyDownEvent != null || KeyUpEvent != null || KeyPressEvent != null))
126.             {
127.                 KeyboardHookStruct MyKeyboardHookStruct = (KeyboardHookStruct) Marshal.PtrToStructure(lParam, typeof(KeyboardHookStruct));
128.                 // raise KeyDown
129.                 if (KeyDownEvent != null && (wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN))
130.                 {
131.                     Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
132.                     KeyEventArgs e = new KeyEventArgs(keyData);
133.                     KeyDownEvent(this, e);
134.                 }
136.                 //键盘按下
137.                 if (KeyPressEvent != null && wParam == WM_KEYDOWN)
138.                 {
139.                     byte[] keyState = new byte[256];
140.                     GetKeyboardState(keyState);
142.                     byte[] inBuffer= new byte[2];
143.                     if (ToAscii(MyKeyboardHookStruct.vkCode,
144.                                 MyKeyboardHookStruct.scanCode,
145.                                 keyState,
146.                                 inBuffer,
147.                                 MyKeyboardHookStruct.flags)==1) 
148.                     {
149.                         KeyPressEventArgs e = new KeyPressEventArgs((char)inBuffer[0]);
150.                         KeyPressEvent(this, e);
151.                     }
152.                 }
154.                 // 键盘抬起 
155.                 if (KeyUpEvent != null && (wParam == WM_KEYUP || wParam == WM_SYSKEYUP))
156.                 {
157.                     Keys keyData=(Keys)MyKeyboardHookStruct.vkCode;
158.                     KeyEventArgs e = new KeyEventArgs(keyData);
159.                     KeyUpEvent(this, e);
160.                 }
162.             }
164.             //如果返回1，则结束消息，这个消息到此为止，不再传递。
165.             //如果返回0或调用CallNextHookEx函数则消息出了这个钩子继续往下传递，也就是传给消息真正的接受者 
166.             return CallNextHookEx(hKeyboardHook, nCode, wParam, lParam); 
167.         }
171.         ~KeyboardHook()
172.         {
173.             Stop();
174.         }
176.     }

180. //以下是调用 
182. private KeyboardHook k_hook;
183. private void HookForm_Load(object sender, EventArgs e)
184.         {
185.         try
186.             {
187.                 if (this.buttonKeyHook.Text == "安装键盘钩子")
188.                 {
189.                     k_hook = new KeyboardHook();
190.                     k_hook.KeyDownEvent += new KeyEventHandler(hook_KeyDown);
191.                     k_hook.Start();
192.                     this.buttonKeyHook.Text = "卸载键盘钩子";
193.                 }else if(k_hook!=null)
194.                 {
195.                     k_hook.Stop();
196.                     this.buttonKeyHook.Text = "安装键盘钩子";
197.                 }
198.             }
199.             catch (Exception ex)
200.             {
201.                 MessageBox.Show(ex.Message);
202.             }
203.         }
205. private void hook_KeyDown(object sender, KeyEventArgs e)
206.         {
207.             //自己写吧 
208.         }