TnbDynamicFunc.h

[詳解]

#pragma once
#include "TnbException.h"
 
 
 
//TNB Library
namespace TNB
{
 
 
 
template<typename FUNC>
class CDynamicFuncT : CCopyImpossible
{
    HMODULE m_hModule;          
    FUNC    m_pFunc;            
    void m_Unload(void)
    {
        if ( m_hModule != NULL )
        {
            ::FreeLibrary(m_hModule);
            m_hModule = NULL;
        }
        m_pFunc = NULL;
    }
public:
 
    CDynamicFuncT(void) : m_hModule(NULL), m_pFunc(NULL)
    {
    }
 
    CDynamicFuncT(LPCSTR lpszDllName, LPCSTR lpszFuncName)
        : m_hModule(NULL), m_pFunc(NULL)
    {
        if ( ! LoadFunc(lpszDllName, lpszFuncName) )
        {
            throw CNullPointerException();
        }
    }
 
    bool LoadFunc(LPCSTR lpszDllName, LPCSTR lpszFuncName)
    {
        m_Unload();
        m_hModule = ::LoadLibraryA(lpszDllName);
        if ( m_hModule != NULL )
        {
            m_pFunc = reinterpret_cast<FUNC>(::GetProcAddressA(m_hModule, lpszFuncName));
        }
        return (m_pFunc != NULL);
    }
 
    ~CDynamicFuncT(void)
    {
        m_Unload();
    }
 
    bool HasFunc(void) const
    {
        return (m_pFunc != NULL);
    }
 
    FUNC operator()(void) const
    {
        if ( m_pFunc == NULL )
        {
            throw CNullPointerException();
        }
        return m_pFunc;
    }
};
 
 
 
template<typename FUNC>
bool GetFuncAddress(FUNC& _pFnc, HINSTANCE hInstance, LPCSTR lpszName)
{
    _pFnc = reinterpret_cast<FUNC>(::GetProcAddressA(hInstance, lpszName));
    return _pFnc != NULL;
}
 
 
 
}; // TNB