VS2010調用Com組件

Com組件開發過程中用的不多，資料也不多，故記錄開發Com組件中的部分問題。

在這一篇文章里，講解了如何使用VS2010創建Com組件。現在基於該文章創建的Com組件接口，創建VC++項目來調用該接口。

使用流程

新建win32控制台項目。

主文件代碼如下：

#include "stdafx.h"
#include "../testCom/testCom_i.h"
#include "../testCom/testCom_i.c"

int _tmain(int argc, _TCHAR* argv[])
{
    HRESULT hr;
    IMyClass *pCom = NULL;
    CoInitialize(NULL);
    hr = CoCreateInstance(CLSID_MyClass,NULL,1,IID_IMyClass,(LPVOID*)&pCom);
    if (SUCCEEDED(hr))
    {
        LONG res;
        pCom->Add(2,3,&res);
        printf("2+3=%d\n",res);
    }
    CoUninitialize();
    return 0;
}

代碼說明：

#include "../testCom/testCom_i.h"

#include "../testCom/testCom_i.c"

是將com組件定義接口的文件包含到本工程中，這樣操作后才可以在后面直接調用Com接口函數。

調用Com組件前必須調用CoInitialize(NULL);

調用完成后需要釋放CoUninitialize();

CoCreateInstance用於創建一個Com實例，函數說明如下：

HRESULT CoCreateInstance(
  __in   REFCLSID rclsid,
  __in   LPUNKNOWN pUnkOuter,
  __in   DWORD dwClsContext,
  __in   REFIID riid,
  __out  LPVOID *ppv
);

rclsid [in] 
The CLSID associated with the data and code that will be used to create the object.

pUnkOuter [in] 
If NULL, indicates that the object is not being created as part of an aggregate. If non-NULL, pointer to the aggregate object's IUnknown interface (the controlling IUnknown). 

dwClsContext [in] 
Context in which the code that manages the newly created object will run. The values are taken from the enumeration CLSCTX. 

riid [in] 
A reference to the identifier of the interface to be used to communicate with the object.

ppv [out] 
Address of pointer variable that receives the interface pointer requested in riid. Upon successful return, * ppv contains the requested interface pointer. Upon failure, * ppv contains NULL.

相關下載

代碼下載