无法在dll文件中调用线程

时间:2011-11-25 20:49:21

标签: c++ multithreading dll

我正在尝试创建一个dll,当你加载它时会创建一个线程 由于某种原因,线程函数没有做任何事情......:\

这是我的代码:

dllthread!= null ..为什么它无效?

#include "stdafx.h"
DWORD WINAPI ThreadProc(
  __in  LPVOID lpParameter
)
{

    std::ofstream myfile;
    myfile.open ("example.txt");
    myfile << "Writing this to a file.\n";
    myfile.close();

    return 0;
}

BOOL APIENTRY DllMain( HMODULE hModule,
                       DWORD  ul_reason_for_call,
                       LPVOID lpReserved
                     )
{

    switch (ul_reason_for_call)
    {
    case DLL_PROCESS_ATTACH:    
        DWORD DllThreadID;
        HANDLE DllThread; //thread's handle

        DllThread=CreateThread(NULL,0,&ThreadProc,0,0,&DllThreadID);
// 
        if (DllThread == NULL)
            MessageBox(NULL, L"Error", L"Error", MB_OK);

        CloseHandle(DllThread);
        break;
    case DLL_THREAD_ATTACH:
    case DLL_THREAD_DETACH:
    case DLL_PROCESS_DETACH:


        break;
    }
    return TRUE;
}

1 个答案:

答案 0 :(得分:11)

而不是从DllMain()启动一个线程,而不是导出一个启动线程的函数:

extern "C" __declspec(dllexport) void start_thread()
{
    DWORD DllThreadID;
    HANDLE DllThread; //thread's handle

    DllThread=CreateThread(NULL,0,ThreadProc,0,0,&DllThreadID);
    if (DllThread == NULL)
        MessageBox(NULL, L"Error", L"Error", MB_OK);
    else
        CloseHandle(DllThread);

}

致电LoadLibrary()后,使用GetProcAddress()访问start_thread()功能。

希望这有帮助。