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  • c#实现屏幕键盘 ScreenKeyBoard

制作者:剑锋冷月 单位:无忧统计网,www.51stat.net
 

  下载完整源代码:http://file.ddvip.com/2008_10/1224821385_ddvip_2422.zip

  要实现一个屏幕键盘,需要监听所有键盘事件,无论窗体是否被激活。因此需要一个全局的钩子,也就

  是系统范围的钩子。

  什么是钩子(Hook)

  钩子(Hook)是Windows提供的一种消息处理机制平台,是指在程序正常运行中接受信息之前预先

  启动的函数,用来检查和修改传给该程序的信息,(钩子)实际上是一个处理消息的程序段,通

  过系统调用,把它挂入系统。每当特定的消息发出,在没有到达目的窗口前,钩子程序就先捕获

  该消息,亦即钩子函数先得到控制权。这时钩子函数即可以加工处理(改变)该消息,也可以不

  作处理而继续传递该消息,还可以强制结束消息的传递。注意:安装钩子函数将会影响系统的性

  能。监测“系统范围事件”的系统钩子特别明显。因为系统在处理所有的相关事件时都将调用您的

  钩子函数,这样您的系统将会明显的减慢。所以应谨慎使用,用完后立即卸载。还有,由于您可

  以预先截获其它进程的消息,所以一旦您的钩子函数出了问题的话必将影响其它的进程。

  钩子的作用范围

  一共有两种范围(类型)的钩子,局部的和远程的。局部钩子仅钩挂自己进程的事件。远程的钩

  子还可以将钩挂其它进程发生的事件。远程的钩子又有两种: 基于线程的钩子将捕获其它进程中

  某一特定线程的事件。简言之,就是可以用来观察其它进程中的某一特定线程将发生的事件。 系

  统范围的钩子将捕捉系统中所有进程将发生的事件消息。 

 

  Hook 类型

  Windows共有14种Hooks,每一种类型的Hook可以使应用程序能够监视不同类型的系统消息处理机

  制。下面描述所有可以利用的Hook类型的发生时机。详细内容可以查阅MSDN,这里只介绍我们将要

  用到的两种类型的钩子。

  (1)WH_KEYBOARD_LL Hook

  WH_KEYBOARD_LL Hook监视输入到线程消息队列中的键盘消息。

  (2)WH_MOUSE_LL Hook

  WH_MOUSE_LL Hook监视输入到线程消息队列中的鼠标消息。

  下面的 class 把 API 调用封装起来以便调用。

1// NativeMethods.cs
2using System;
3using System.Runtime.InteropServices;
4using System.Drawing;
5
6namespace CnBlogs.Youzai.ScreenKeyboard {
7  [StructLayout(LayoutKind.Sequential)]
8  internal struct MOUSEINPUT {
9    public int dx;
10    public int dy;
11    public int mouseData;
12    public int dwFlags;
13    public int time;
14    public IntPtr dwExtraInfo;
15  }
16
17  [StructLayout(LayoutKind.Sequential)]
18  internal struct KEYBDINPUT {
19    public short wVk;
20    public short wScan;
21    public int dwFlags;
22    public int time;
23    public IntPtr dwExtraInfo;
24  }
25
26  [StructLayout(LayoutKind.Explicit)]
27  internal struct Input {
28    [FieldOffset(0)]
29    public int type;
30    [FieldOffset(4)]
31    public MOUSEINPUT mi;
32    [FieldOffset(4)]
33    public KEYBDINPUT ki;
34    [FieldOffset(4)]
35    public HARDWAREINPUT hi;
36  }
37
38  [StructLayout(LayoutKind.Sequential)]
39  internal struct HARDWAREINPUT {
40    public int uMsg;
41    public short wParamL;
42    public short wParamH;
43  }
44
45  internal class INPUT {
46    public const int MOUSE = 0;
47    public const int KEYBOARD = 1;
48    public const int HARDWARE = 2;
49  }
50
51  internal static class NativeMethods {
52    [DllImport("User32.dll", CharSet = CharSet.Auto, SetLastError = false)]
53    internal static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);
54
55    [DllImport("User32.dll", CharSet = CharSet.Auto, SetLastError = false)]
56    internal static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
57
58    [DllImport("User32.dll", EntryPoint = "SendInput", CharSet = CharSet.Auto)]
59    internal static extern UInt32 SendInput(UInt32 nInputs, Input[] pInputs, Int32 cbSize);
60
61    [DllImport("Kernel32.dll", EntryPoint = "GetTickCount", CharSet = CharSet.Auto)]
62    internal static extern int GetTickCount();
63
64    [DllImport("User32.dll", EntryPoint = "GetKeyState", CharSet = CharSet.Auto)]
65    internal static extern short GetKeyState(int nVirtKey);
66
67    [DllImport("User32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Auto)]
68    internal static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
69  }
70}

安装钩子

 

  使用SetWindowsHookEx函数(API函数),指定一个Hook类型、自己的Hook过程是全局还是局部Hook,

  同时给出Hook过程的进入点,就可以轻松的安装自己的Hook过程。SetWindowsHookEx总是将你的Hook函

  数放置在Hook链的顶端。你可以使用CallNextHookEx函数将系统消息传递给Hook链中的下一个函数。

  对于某些类型的Hook,系统将向该类的所有Hook函数发送消息,这时,

  Hook函数中的CallNextHookEx语句将被忽略。全局(远程钩子)Hook函数可以拦截系统中所有线程的某

  个特定的消息,为了安装一个全局Hook过程,必须在应用程序外建立一个DLL并将该Hook函数封装到其中,

  应用程序在安装全局Hook过程时必须先得到该DLL模块的句柄。将Dll名传递给LoadLibrary 函数,就会得

  到该DLL模块的句柄;得到该句柄 后,使用GetProcAddress函数可以得到Hook过程的地址。最后,使用

  SetWindowsHookEx将 Hook过程的首址嵌入相应的Hook链中,SetWindowsHookEx传递一个模块句柄,它为

  Hook过程的进入点,线程标识符置为0,该Hook过程同系统中的所有线程关联。如果是安装局部Hook此时

  该Hook函数可以放置在DLL中,也可以放置在应用程序的模块段。在C#中通过平台调用(前文已经介绍过)

  来调用API函数。

1  public void Start(bool installMouseHook, bool installKeyboardHook) {
2    if (hMouseHook == IntPtr.Zero && installMouseHook) {
3      MouseHookProcedure = new HookProc(MouseHookProc);
4      hMouseHook = SetWindowsHookEx(
5        WH_MOUSE_LL,
6        MouseHookProcedure,
7        Marshal.GetHINSTANCE(
8        Assembly.GetExecutingAssembly().GetModules()[0]),
9        0
10      );
11
12      if (hMouseHook == IntPtr.Zero) {
13        int errorCode = Marshal.GetLastWin32Error();
14        Stop(true, false, false);
15
16        throw new Win32Exception(errorCode);
17      }
18    }
19
20    if (hKeyboardHook == IntPtr.Zero && installKeyboardHook) {
21      KeyboardHookProcedure = new HookProc(KeyboardHookProc);
22      //install hook
23      hKeyboardHook = SetWindowsHookEx(
24        WH_KEYBOARD_LL,
25        KeyboardHookProcedure,
26        Marshal.GetHINSTANCE(
27        Assembly.GetExecutingAssembly().GetModules()[0]),
28        0);
29      // If SetWindowsHookEx fails.
30      if (hKeyboardHook == IntPtr.Zero) {
31        // Returns the error code returned by the last
32        // unmanaged function called using platform invoke
33        // that has the DllImportAttribute.SetLastError flag set.
34        int errorCode = Marshal.GetLastWin32Error();
35        //do cleanup
36        Stop(false, true, false);
37        //Initializes and throws a new instance of the
38        // Win32Exception class with the specified error.
39        throw new Win32Exception(errorCode);
40      }
41    }
42  }

使用完钩子后,要进行卸载,这个可以写在析构函数中。

 

1
2  public void Stop() {
3    this.Stop(true, true, true);
4  }
5  
6  public void Stop(bool uninstallMouseHook, bool uninstallKeyboardHook,
7    bool throwExceptions) {
8    // if mouse hook set and must be uninstalled
9    if (hMouseHook != IntPtr.Zero && uninstallMouseHook) {
10      // uninstall hook
11      bool retMouse = UnhookWindowsHookEx(hMouseHook);
12      // reset invalid handle
13      hMouseHook = IntPtr.Zero;
14      // if failed and exception must be thrown
15      if (retMouse == false && throwExceptions) {
16        // Returns the error code returned by the last unmanaged function
17        // called using platform invoke that has the DllImportAttribute.
18        // SetLastError flag set.
19        int errorCode = Marshal.GetLastWin32Error();
20        // Initializes and throws a new instance of the Win32Exception class
21        // with the specified error.
22        throw new Win32Exception(errorCode);
23      }
24    }
25
26    // if keyboard hook set and must be uninstalled
27    if (hKeyboardHook != IntPtr.Zero && uninstallKeyboardHook) {
28      // uninstall hook
29      bool retKeyboard = UnhookWindowsHookEx(hKeyboardHook);
30      // reset invalid handle
31      hKeyboardHook = IntPtr.Zero;
32      // if failed and exception must be thrown
33      if (retKeyboard == false && throwExceptions) {
34        // Returns the error code returned by the last unmanaged function
35        // called using platform invoke that has the DllImportAttribute.
36        // SetLastError flag set.
37        int errorCode = Marshal.GetLastWin32Error();
38        // Initializes and throws a new instance of the Win32Exception class
39        // with the specified error.
40        throw new Win32Exception(errorCode);
41      }
42    }
43  }
44

将这个文件编译成一个dll,即可在应用程序中调用。通过它提供的事件,便可监听所有的键盘事件。

 

  但是,这只能监听键盘事件,没有键盘的情况下,怎么会有键盘事件?其实很简单,通过SendInput

  API函数提供虚拟键盘代码的调用即可模拟键盘输入。下面的代码模拟一个 KeyDown 和 KeyUp 过程,

  把他们连接起来就是一次按键过程。

1  private void SendKeyDown(short key) {
2    Input[] input = new Input[1];
3    input[0].type = INPUT.KEYBOARD;
4    input[0].ki.wVk = key;
5    input[0].ki.time = NativeMethods.GetTickCount();
6
7    if (NativeMethods.SendInput((uint)input.Length, input, Marshal.SizeOf(input[0]))
8      < input.Length) {
9      throw new Win32Exception(Marshal.GetLastWin32Error());
10    }
11  }
12
13  private void SendKeyUp(short key) {
14    Input[] input = new Input[1];
15    input[0].type = INPUT.KEYBOARD;
16    input[0].ki.wVk = key;
17    input[0].ki.dwFlags = KeyboardConstaint.KEYEVENTF_KEYUP;
18    input[0].ki.time = NativeMethods.GetTickCount();
19
20    if (NativeMethods.SendInput((uint)input.Length, input, Marshal.SizeOf(input[0]))
21      < input.Length) {
22      throw new Win32Exception(Marshal.GetLastWin32Error());
23    }
24  }

自己实现一个 KeyBoardButton 控件用作按钮,用 Visual Studio 或者 SharpDevelop 为屏幕键盘设计 UI,然后

  在这些 Button 的 Click 事件里面模拟一个按键过程。

 

1
2  private void ButtonOnClick(object sender, EventArgs e) {
3    KeyboardButton btnKey = sender as KeyboardButton;
4    if (btnKey == null) {
5      return;
6    }
7
8    SendKeyCommand(btnKey);
9  }
10  
11  private void SendKeyCommand(KeyboardButton keyButton) {
12    short key = keyButton.VKCode;
13    if (combinationVKButtonsMap.ContainsKey(key)) {
14      if (keyButton.Checked) {
15        SendKeyUp(key);
16      } else {
17        SendKeyDown(key);
18      }
19    } else {
20      SendKeyDown(key);
21      SendKeyUp(key);
22    }
23  }

其中 combinationVKButtonsMap 是一个 IDictionary<short, IList<KeyboardButton>>, key 存储的是

  VK_SHIFT, VK_CONTROL 等组合键的键盘码。左右两个按钮对应同一个键盘码,因此需要放在一个 List 里。

  标准键盘上的每一个键都有虚拟键码( VK_CODE)与之对应。还有一些其他的常量,

  把它写在一个静态 class 里吧。

1  // KeyboardConstaint.cs
2  internal static class KeyboardConstaint {
3    internal static readonly short VK_F1 = 0x70;
4    internal static readonly short VK_F2 = 0x71;
5    internal static readonly short VK_F3 = 0x72;
6    internal static readonly short VK_F4 = 0x73;
7    internal static readonly short VK_F5 = 0x74;
8    internal static readonly short VK_F6 = 0x75;
9    internal static readonly short VK_F7 = 0x76;
10    internal static readonly short VK_F8 = 0x77;
11    internal static readonly short VK_F9 = 0x78;
12    internal static readonly short VK_F10 = 0x79;
13    internal static readonly short VK_F11 = 0x7A;
14    internal static readonly short VK_F12 = 0x7B;
15
16    internal static readonly short VK_LEFT = 0x25;
17    internal static readonly short VK_UP = 0x26;
18    internal static readonly short VK_RIGHT = 0x27;
19    internal static readonly short VK_DOWN = 0x28;
20
21    internal static readonly short VK_NONE = 0x00;
22    internal static readonly short VK_ESCAPE = 0x1B;
23    internal static readonly short VK_EXECUTE = 0x2B;
24    internal static readonly short VK_CANCEL = 0x03;
25    internal static readonly short VK_RETURN = 0x0D;
26    internal static readonly short VK_ACCEPT = 0x1E;
27    internal static readonly short VK_BACK = 0x08;
28    internal static readonly short VK_TAB = 0x09;
29    internal static readonly short VK_DELETE = 0x2E;
30    internal static readonly short VK_CAPITAL = 0x14;
31    internal static readonly short VK_NUMLOCK = 0x90;
32    internal static readonly short VK_SPACE = 0x20;
33    internal static readonly short VK_DECIMAL = 0x6E;
34    internal static readonly short VK_SUBTRACT = 0x6D;
35
36    internal static readonly short VK_ADD = 0x6B;
37    internal static readonly short VK_DIVIDE = 0x6F;
38    internal static readonly short VK_MULTIPLY = 0x6A;
39    internal static readonly short VK_INSERT = 0x2D;
40
41    internal static readonly short VK_OEM_1 = 0xBA; // ';:' for US
42    internal static readonly short VK_OEM_PLUS = 0xBB; // '+' any country
43
44    internal static readonly short VK_OEM_MINUS = 0xBD; // '-' any country
45
46    internal static readonly short VK_OEM_2 = 0xBF; // '/?' for US
47    internal static readonly short VK_OEM_3 = 0xC0; // '`~' for US
48    internal static readonly short VK_OEM_4 = 0xDB; // '[{' for US
49    internal static readonly short VK_OEM_5 = 0xDC; // '|' for US
50    internal static readonly short VK_OEM_6 = 0xDD; // ']}' for US
51    internal static readonly short VK_OEM_7 = 0xDE; // ''"' for US
52    internal static readonly short VK_OEM_PERIOD = 0xBE; // '.>' any country
53    internal static readonly short VK_OEM_COMMA = 0xBC; // ',<' any country
54    internal static readonly short VK_SHIFT = 0x10;
55    internal static readonly short VK_CONTROL = 0x11;
56    internal static readonly short VK_MENU = 0x12;
57    internal static readonly short VK_LWIN = 0x5B;
58    internal static readonly short VK_RWIN = 0x5C;
59    internal static readonly short VK_APPS = 0x5D;
60
61    internal static readonly short VK_LSHIFT = 0xA0;
62    internal static readonly short VK_RSHIFT = 0xA1;
63    internal static readonly short VK_LCONTROL = 0xA2;
64    internal static readonly short VK_RCONTROL = 0xA3;
65    internal static readonly short VK_LMENU = 0xA4;
66    internal static readonly short VK_RMENU = 0xA5;
67
68    internal static readonly short VK_SNAPSHOT = 0x2C;
69    internal static readonly short VK_SCROLL = 0x91;
70    internal static readonly short VK_PAUSE = 0x13;
71    internal static readonly short VK_HOME = 0x24;
72
73    internal static readonly short VK_NEXT = 0x22;
74    internal static readonly short VK_PRIOR = 0x21;
75    internal static readonly short VK_END = 0x23;
76
77    internal static readonly short VK_NUMPAD0 = 0x60;
78    internal static readonly short VK_NUMPAD1 = 0x61;
79    internal static readonly short VK_NUMPAD2 = 0x62;
80    internal static readonly short VK_NUMPAD3 = 0x63;
81    internal static readonly short VK_NUMPAD4 = 0x64;
82    internal static readonly short VK_NUMPAD5 = 0x65;
83    internal static readonly short VK_NUMPAD5NOTHING = 0x0C;
84    internal static readonly short VK_NUMPAD6 = 0x66;
85    internal static readonly short VK_NUMPAD7 = 0x67;
86    internal static readonly short VK_NUMPAD8 = 0x68;
87    internal static readonly short VK_NUMPAD9 = 0x69;
88
89    internal static readonly short KEYEVENTF_EXTENDEDKEY  = 0x0001;
90    internal static readonly short KEYEVENTF_KEYUP     = 0x0002;
91
92    internal static readonly int GWL_EXSTYLE  = -20;
93    internal static readonly int WS_DISABLED  = 0X8000000;
94    internal static readonly int WM_SETFOCUS  = 0X0007;
95  }

屏幕键盘必须是一个不能获得输入焦点的窗体,在这个窗体的构造函数里,可以安装

 

  一个全局鼠标钩子,再通过调用 SetWindowLong API 函数完成。

1UserActivityHook hook = new UserActivityHook(true, true);
2hook.MouseActivity += HookOnMouseActivity;
3
4private void HookOnMouseActivity(object sener, HookEx.MouseExEventArgs e) {
5  Point location = e.Location;
6
7  if (e.Button == MouseButtons.Left) {
8    Rectangle captionRect = new Rectangle(this.Location, new Size(this.Width,
9      SystemInformation.CaptionHeight));
10    if (captionRect.Contains(location)) {
11      NativeMethods.SetWindowLong(this.Handle, KeyboardConstaint.GWL_EXSTYLE,
12        (int)NativeMethods.GetWindowLong(this.Handle, KeyboardConstaint.GWL_EXSTYLE)
13         & (~KeyboardConstaint.WS_DISABLED));
14      NativeMethods.SendMessage(this.Handle, KeyboardConstaint.WM_SETFOCUS, IntPtr.Zero, IntPtr.Zero);
15    } else {
16      NativeMethods.SetWindowLong(this.Handle, KeyboardConstaint.GWL_EXSTYLE,
17        (int)NativeMethods.GetWindowLong(this.Handle, KeyboardConstaint.GWL_EXSTYLE) |
18         KeyboardConstaint.WS_DISABLED);
19    }
20  }
21}

  鼠标单击标题栏,让屏幕键盘可以接收焦点,并激活,单击其他部分则不激活窗体(如果激活了,其他程序必然取消激活,

  输入就无法进行了),这样才可以进行输入,并且保证了可以拖动窗体到其他位置。

 

  至此,一个屏幕键盘程序差不多完成了,能够实现与实际键盘完全同步。至于窗体,按键重绘,以及 Num Lock, Caps Lock,

  Scroll Lock 等键盘灯的模拟,这里就不讲了,如果有兴趣,可以下载完整的代码。最后我们的屏幕键盘程序运行的效果如

  下图:

  C# 实现屏幕键盘 (ScreenKeyboard)

  http://www.cnblogs.com/youzai/archive/2008/05/19/1202732.html

 

 

  Hook 类型

  Windows共有14种Hooks,每一种类型的Hook可以使应用程序能够监视不同类型的系统消息处理机

  制。下面描述所有可以利用的Hook类型的发生时机。详细内容可以查阅MSDN,这里只介绍我们将要

  用到的两种类型的钩子。

  (1)WH_KEYBOARD_LL Hook

  WH_KEYBOARD_LL Hook监视输入到线程消息队列中的键盘消息。

  (2)WH_MOUSE_LL Hook

  WH_MOUSE_LL Hook监视输入到线程消息队列中的鼠标消息。

  下面的 class 把 API 调用封装起来以便调用。

1// NativeMethods.cs
2using System;
3using System.Runtime.InteropServices;
4using System.Drawing;
5
6namespace CnBlogs.Youzai.ScreenKeyboard {
7  [StructLayout(LayoutKind.Sequential)]
8  internal struct MOUSEINPUT {
9    public int dx;
10    public int dy;
11    public int mouseData;
12    public int dwFlags;
13    public int time;
14    public IntPtr dwExtraInfo;
15  }
16
17  [StructLayout(LayoutKind.Sequential)]
18  internal struct KEYBDINPUT {
19    public short wVk;
20    public short wScan;
21    public int dwFlags;
22    public int time;
23    public IntPtr dwExtraInfo;
24  }
25
26  [StructLayout(LayoutKind.Explicit)]
27  internal struct Input {
28    [FieldOffset(0)]
29    public int type;
30    [FieldOffset(4)]
31    public MOUSEINPUT mi;
32    [FieldOffset(4)]
33    public KEYBDINPUT ki;
34    [FieldOffset(4)]
35    public HARDWAREINPUT hi;
36  }
37
38  [StructLayout(LayoutKind.Sequential)]
39  internal struct HARDWAREINPUT {
40    public int uMsg;
41    public short wParamL;
42    public short wParamH;
43  }
44
45  internal class INPUT {
46    public const int MOUSE = 0;
47    public const int KEYBOARD = 1;
48    public const int HARDWARE = 2;
49  }
50
51  internal static class NativeMethods {
52    [DllImport("User32.dll", CharSet = CharSet.Auto, SetLastError = false)]
53    internal static extern IntPtr GetWindowLong(IntPtr hWnd, int nIndex);
54
55    [DllImport("User32.dll", CharSet = CharSet.Auto, SetLastError = false)]
56    internal static extern IntPtr SetWindowLong(IntPtr hWnd, int nIndex, int dwNewLong);
57
58    [DllImport("User32.dll", EntryPoint = "SendInput", CharSet = CharSet.Auto)]
59    internal static extern UInt32 SendInput(UInt32 nInputs, Input[] pInputs, Int32 cbSize);
60
61    [DllImport("Kernel32.dll", EntryPoint = "GetTickCount", CharSet = CharSet.Auto)]
62    internal static extern int GetTickCount();
63
64    [DllImport("User32.dll", EntryPoint = "GetKeyState", CharSet = CharSet.Auto)]
65    internal static extern short GetKeyState(int nVirtKey);
66
67    [DllImport("User32.dll", EntryPoint = "SendMessage", CharSet = CharSet.Auto)]
68    internal static extern IntPtr SendMessage(IntPtr hWnd, int msg, IntPtr wParam, IntPtr lParam);
69  }
70}

安装钩子



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