[問題] *handle的用法?
小弟是C++剛入門的新手，最近在研究一個呼叫DLL的程式，
爬了文也google過，想了很久但還是有些地方不太了解。
希望各位大大給點意見.
程式碼:
typedef void *DEV_HANDLE; //line 1
DEV_HANDLE WINAPI Device_xOpen(const int nDevIndex); //line 2
typedef DEV_HANDLE (WINAPI *LP_DevOpen)(const int nDevIndex,
const char *pDevName); // line 3
DEV_HANDLE m_hLink; // line 4
LP_DevOpen m_Open; // line 5
m_Open = (LP_DevOpen)::GetProcAddress(hDLL, "Device_xOpen"); // line 6
m_hLink = m_Open(0, ""); // line 7
if (m_hLink){ ......} // line 8
疑問:
1. DEV_HANDEL為指標型式，所以 line 2 的意思是函式Device_xOpen的回傳值
是一個位址嗎?
2. 如果"函式Device_xOpen的回傳值是一個位址"，
那為何line 7, line 8 看起來 m_hLink 是一個值?
3. Device_xOpen函式的輸入值只有一個nDevIndex，
經過了line 3, line 6可以多出一個pDevName的原因是?
pDevName在原本的Device_xOpen沒有，它代表的是甚麼呢?
4. 雙冒號::是用在表示Class裡的函式或是變數，
但line 6 中的(LP_DevOpen)::GetProcAddress雙冒號的用意是?
5. 雙冒號::另一問，程式碼:
HINSTANCE hInst = ::LoadLibrary ( “HIDKey.dll” );
這裡的雙冒號的用意是?
C++真的比想像中的還有學問 >_<
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※ 編輯: sv39933993 (111.250.184.78), 08/14/2014 00:16:40
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