將指針傳遞給proc作爲參數

Question

我想傳遞一個指向C++過程的指針。我嘗試傳遞這個LRESULT（*）（HWND，UINT，WPARAM，LPARAM）prc，但它不起作用。這是如何完成的？

感謝

HWND OGLFRAME::create(HWND parent, LRESULT(*)(HWND, UINT, WPARAM, LPARAM) prc) 
{ 
    if(framehWnd != NULL) 
    { 
     return framehWnd; 
     ZeroMemory(&rwc,sizeof(rwc)); 

    } 

}

通過 「沒用」 我的意思是這是一個語法錯誤。

from the compiler: 
Error 2 error C3646: 'prc' : unknown override specifier c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.h 10 
Error 5 error C3646: 'prc' : unknown override specifier c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.cpp 7 
Error 1 error C2146: syntax error : missing ')' before identifier 'prc' c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.h 10 
Error 4 error C2146: syntax error : missing ')' before identifier 'prc' c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.cpp 7 
Error 3 error C2059: syntax error : ')' c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.h 10 
Error 6 error C2059: syntax error : ')' c:\users\josh\documents\visual studio 2008\projects\vectorizer project\vectorizer project\oglframe.cpp 7 

Answer 1

HWND OGLFRAME::create(HWND parent, LRESULT(*prc)(HWND, UINT, WPARAM, LPARAM)) 

你也可以只使用WNDPROC類型：

HWND OGLFRAME::create(HWND parent, WNDPROC prc) 

Answer 2

試試這個：

HWND OGLFRAME::create(HWND parent, LRESULT(*wndproc)(HWND, UINT, WPARAM, LPARAM)) 
{ 

} 

Answer 3

要聲明一個接受一個函數指針的函數：

// Note the CALLBACK calling convention! 
HWND OGLFRAME::create(HWND parent, 
    LRESULT (CALLBACK *prc)(HWND, UINT, WPARAM, LPARAM)) 
{ 
    // ... 
} 

要傳遞函數指針：

// Note the CALLBACK calling convention! 
LRESULT CALLBACK MyProc(HWND, UINT, WPARAM, LPARAM) 
{ 
    // ... 
} 

// Note the ampersand! 
oglframeinstance.create(hwnd, &MyProc);