DLL 学习2

学习资料：

dl中如何装入文档和窗口(其实很简单，看DLL 学习3）

http://www.codeproject.com/KB/docview/sdicviewdll.aspx

http://www.codeproject.com/KB/docview/docviewfromdll.aspx

extern "C" AFX_EXT_API UINT Init(CRuntimeClass** view)
{
    // Replace YourDLLName with the AFX_EXTENSION_MODULE variable above
    // your DllMain.
    new CDynLinkLibrary(Dll4DLL);    //Dll4DLL为我当前的DLL名
    // Replace CYourClass with the name of CView derived class you are exposing.
    *view = RUNTIME_CLASS(CMyFormView); //CMyFormView是我的类
    return(0);
}

注释：

1.AFX_EXT_API   是   MFC   Extension   DLL   可以使用的一个宏，定义成  
  #ifdef   _AFXEXT  
  #define   AFX_EXT_API         __declspec(   dllexport   )  
  #else  
  #define   AFX_EXT_API         __declspec(   dllimport   )  
  #endif

DLL调用程序

void CMainFrame::OnViewLoadviewfromdll() 
{
    typedef UINT ( * LPDLLFUNC)(CRuntimeClass**);
    LPDLLFUNC lpfnDllFunc = NULL;
    HINSTANCE hDLL = NULL;     	  
    hDLL = LoadLibrary("Dll4.dll");
    
    if(hDLL)
    {
        lpfnDllFunc = (LPDLLFUNC)::GetProcAddress(hDLL,"Init");
        if (!lpfnDllFunc)
	{
	    AfxMessageBox("Function not found in DLL");
	    FreeLibrary(hDLL);
	    return;
	}
	CRuntimeClass* pNewViewClass;
	lpfnDllFunc(&pNewViewClass);
	ASSERT(pNewViewClass);
	CSdiDllFramesDoc* pDoc = (CSdiDllFramesDoc*) GetActiveDocument();
	ASSERT(pDoc); // Hmm, do we need this?
	pDoc->SwitchToView(pNewViewClass);	
    }
    else
    {
        AfxMessageBox("Dll not found!");//DLL 装载失败
    }
}