如何将void（__thiscall MyClass :: *）（void *）转换为void（__cdecl *）（void *）指针

Question

我想构建一个可以隐藏线程创建的“IThread”类。子类实现“ThreadMain”方法，并自动调用它看起来像这样：

class IThread 
{ 
public: 
    void BeginThread(); 
    virtual void ThreadMain(void *) PURE; 
}; 
void IThread::BeginThread() 
{ 
    //Error : cannot convert"std::binder1st<_Fn2>" to "void (__cdecl *)(void *)" 
    m_ThreadHandle = _beginthread(
        std::bind1st(std::mem_fun(&IThread::ThreadMain), this), 
        m_StackSize, NULL); 
    //Error : cannot convert void (__thiscall*)(void *) to void (__cdecl *)(void *) 
     m_ThreadHandle = _beginthread(&IThread::ThreadMain, m_StackSize, NULL); 
} 

我已经搜索周围，无法弄清楚。有没有人做过这样的事情？或者我走错路了？ TIA

Answer 1

你不能。

您应该使用静态函数（不是静态成员函数，而是自由函数）。

// IThread.h 
class IThread 
{ 
public: 
    void BeginThread(); 
    virtual void ThreadMain() = 0; 
}; 

// IThread.cpp 
extern "C" 
{ 
    static void __cdecl IThreadBeginThreadHelper(void* userdata) 
    { 
     IThread* ithread = reinterpret_cast< IThread* >(userdata); 
     ithread->ThreadMain(); 
    } 
} 
void IThread::BeginThread() 
{ 
    m_ThreadHandle = _beginthread(
        &IThreadBeginThreadHelper, 
        m_StackSize, reinterpret_cast< void* >(this)); 
}