输入语言钩子

Question

我正在编写一个需要获取系统输入语言的应用程序，而应用程序窗口是没有关注。

在搜索Google后，我发现执行此操作的方法是挂钩WM_INPUTLANGCHANGE消息。

但我找不到钩子的语法示例。

我发现下面的代码，并试图修改它以适应我的需要，但我失败了：

编辑： 我已经取代WM_KEYUP与WM_INPUTLANGCHANGE但它没有工作。

using System; 
using System.Collections.Generic; 
using System.Diagnostics; 
using System.Runtime.InteropServices; 
using System.Windows.Forms; 

namespace KeyHook 
{ 
    class LenHook 
    { 

     private const int WM_INPUTLANGCHANGE = 0x0051; 
     private static LowLevelKeyboardProc _proc = HookCallback; 
     private static IntPtr _hookID = IntPtr.Zero; 


     [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
     private static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId); 

     [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
     [return: MarshalAs(UnmanagedType.Bool)] 
     public static extern bool UnhookWindowsHookEx(IntPtr hhk); 

     [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
     public static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam); 

     [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
     public static extern IntPtr GetModuleHandle(string lpModuleName); 


     private delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam); 


     public LenHook() 
     { 


      _hookID = SetHook(_proc); 
      UnhookWindowsHookEx(_hookID); 
      System.Windows.Forms.Application.Run(); 


     } 
     //Install hook 
     private static IntPtr SetHook(LowLevelKeyboardProc proc) 
     { 
      using (var curProcess = Process.GetCurrentProcess()) 
      { 
       using (var curModule = curProcess.MainModule) 
       { 
        return SetWindowsHookEx(WM_INPUTLANGCHANGE, proc, GetModuleHandle(curModule.ModuleName), 0); 
       } 
      } 
     } 

     //Do it when key press 
     private static IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam) 
     { 

      MessageBox.Show(wParam.ToString()); 
      return CallNextHookEx(_hookID, nCode, wParam, lParam); 
     } 
    } 
} 

Answer 1

从我的一个项目此代码的工作对我来说，它看起来像我们可能会使用相同的例子：

private static IntPtr _hookId = IntPtr.Zero; 
private readonly External.LowLevelKeyboardProc _proc; 

public FrmMain() 
{ 
    _proc = HookCallback; 
    _hookId = SetHook(_proc); 
    InitializeComponent(); 
} 

private static IntPtr SetHook(External.LowLevelKeyboardProc proc) 
{ 
    using(var curProcess = Process.GetCurrentProcess()) 
    { 
     using(var curModule = curProcess.MainModule) 
     { 
      return External.SetWindowsHookEx(External.WH_KEYBOARD_LL, proc, External.GetModuleHandle(curModule.ModuleName), 0); 
     } 
    } 
} 

private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam) 
{ 
    // You can change this to WM_KEYDOWN 
    if (nCode >= 0 && wParam == (IntPtr)External.WM_KEYUP) 
    { 
     // Code you want to run when a button is pressed. 
    } 
    return External.CallNextHookEx(_hookId, nCode, wParam, lParam); 
} 

此外，这是我的External类。

public static class External 
{ 
    public delegate IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam); 

    public const int WH_KEYBOARD_LL = 13; 
    public const int WM_KEYDOWN = 0x0100; 
    public const int WM_KEYUP = 0x0101; 
    public const uint WM_GETTEXT = 0x0D; 
    public const uint WM_GETTEXTLENGTH = 0x0E; 
    public const uint EM_GETSEL = 0xB0; 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern IntPtr GetForegroundWindow(); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern uint GetWindowThreadProcessId(IntPtr hWnd, out uint lpdwProcessId); 

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern uint GetCurrentThreadId(); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern bool AttachThreadInput(uint idAttach, uint idAttachTo, bool fAttach); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern IntPtr GetFocus(); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern int SendMessage(IntPtr hWnd, uint Msg, int wParam, StringBuilder lParam); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern int SendMessage(IntPtr hWnd, uint Msg, out int wParam, out int lParam); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern IntPtr SetWindowsHookEx(int idHook, LowLevelKeyboardProc lpfn, IntPtr hMod, uint dwThreadId); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    [return: MarshalAs(UnmanagedType.Bool)] 
    public static extern bool UnhookWindowsHookEx(IntPtr hhk); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern IntPtr CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam); 

    [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern IntPtr GetModuleHandle(string lpModuleName); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern bool GetCaretPos(out Point lPoint); 

    [DllImport("user32.dll", CharSet = CharSet.Auto, SetLastError = true)] 
    public static extern int GetClassName(IntPtr hWnd, StringBuilder lpClassName, int nMaxCount); 
} 

我已阅读，你就会有问题，如果你尝试从一个控制台应用程序做这些挂钩，尽管你到Application.Run()调用应该解决这个问题。