1.假如我们创建的Com组件的工程名叫TestCom,在其中添加了一个接口叫MyCom,接口名会自动命名为IMyCom,在其中添加两个方法，分别为：

C++代码  

1. HRESULT Add([in] long n1,[in] long n2,[out,retval]long * pVal);
2. HRESULT Cat([in] BSTR s1,[in] BSTR s2,[out,retval] BSTR * pVal);

HRESULT Add([in] long n1,[in] long n2,[out,retval]long * pVal);
HRESULT Cat([in] BSTR s1,[in] BSTR s2,[out,retval] BSTR * pVal);

编绎成功后，会生成TestCom.dll
注意此时我们生成的Com组件层次即为：TestCom.IMycom.方法;

2.下面总结出调用该Com的几种方法：

Cpp代码  

1. #include "stdafx.h"
2. #include <atlbase.h>
3. #import "G:\\workspace\\VC_WorkSpace\\TestCom\\Debug\\TestCom.dll" no_namespace

#include "stdafx.h"
#include <atlbase.h>
#import "G:\\workspace\\VC_WorkSpace\\TestCom\\Debug\\TestCom.dll" no_namespace

/*
注意：在导入了com的dll后，会在工程的exe目录下生成两个文件：TestCom.tlh与TestCom.tli,一个为定义文件，一个为实现文件，打开TestCom.tlh定义文件，会发现有类似这样几句：

_COM_SMARTPTR_TYPEDEF(IMyCom, __uuidof(IMyCom)); //该宏定义了指向接口IMyCom的指针IMyComPtr,以后的程序中可以直接用IMyComPtr这个指针类型。

struct __declspec(uuid("92e83a37-399a-47b1-bf6c-0ab052650cfe"))
MyCom; //该句定义了CLSID为"{92e83a37-399a-47b1-bf6c-0ab052650cfe}",通过它我们可以通过CLSIDFromString获取clsid;

struct __declspec(uuid("103b4c6e-3d3e-4e38-ab50-b9348465fc13"))
IMyCom : IDispatch //该句定义了接口ID:IID为"{103b4c6e-3d3e-4e38-ab50-b9348465fc13}",通过它我们可以通过IIDFromString获取接口iid;

CoCreateInstance函数就用到了上面两个做为参数来创建Com对象.
*/

第一种方法：

Cpp代码  

1. int impl0()
2. {
3. CoInitialize(NULL);
4. CLSID clsid;
5. IID iid;
6. HRESULT hr = CLSIDFromString(OLESTR("{92e83a37-399a-47b1-bf6c-0ab052650cfe}"),&clsid);
7. if(NOERROR != hr){
8. MessageBox(NULL,"ErrCLSIDFromString","ErrCLSIDFromString",MB_OK);
9. return -1;
10. }
11. HRESULT hriid = IIDFromString(OLESTR("{103b4c6e-3d3e-4e38-ab50-b9348465fc13}"),&iid);
12. if(S_OK != hriid){
13. MessageBox(NULL,"ErrIIDFromString","ErrIIDFromString",MB_OK);
14. return -1;
15. }
16. {
17. CComPtr<imycom> pMyCom;
18. pMyCom.CoCreateInstance(clsid);
19. long ret;
20. ret = pMyCom->Add(1,2);
21. }
22. CoUninitialize();
23. return 0;
24. }

int impl0()
{
CoInitialize(NULL);
CLSID clsid;
IID iid;
HRESULT hr = CLSIDFromString(OLESTR("{92e83a37-399a-47b1-bf6c-0ab052650cfe}"),&clsid);
if(NOERROR != hr){
MessageBox(NULL,"ErrCLSIDFromString","ErrCLSIDFromString",MB_OK);
return -1;
}HRESULT hriid = IIDFromString(OLESTR("{103b4c6e-3d3e-4e38-ab50-b9348465fc13}"),&iid);
if(S_OK != hriid){
MessageBox(NULL,"ErrIIDFromString","ErrIIDFromString",MB_OK);
return -1;
}{
CComPtr<imycom> pMyCom;
pMyCom.CoCreateInstance(clsid);
long ret;
ret = pMyCom->Add(1,2);
}
CoUninitialize();
return 0;
}

第二种方法：

Cpp代码  

1. int impl1()
2. {
3. CoInitialize(NULL);
4. CLSID clsid;
5. CLSIDFromProgID(OLESTR("TestCom.MyCom"),&clsid); //"TestCom.MyCom"即为Dll名+Com对象名
6. {
7. CComPtr<imycom> pMyCom;
8. pMyCom.CoCreateInstance(clsid);
9. long ret;
10. ret = pMyCom->Add(1,2);
11. }
12. CoUninitialize();
13. return 0;
14. }

int impl1()
{
CoInitialize(NULL);
CLSID clsid;
CLSIDFromProgID(OLESTR("TestCom.MyCom"),&clsid); //"TestCom.MyCom"即为Dll名+Com对象名
{
CComPtr<imycom> pMyCom;
pMyCom.CoCreateInstance(clsid);
long ret;
ret = pMyCom->Add(1,2);
}
CoUninitialize();
return 0;
}

第三种方法：

Cpp代码  

1. int impl2()
2. {
3. CoInitialize(NULL);
4. IMyComPtr Pt ;
5. if (!SUCCEEDED(Pt.CreateInstance(__uuidof(MyCom))))
6. {
7. DWORD err;
8. err = GetLastError();
9. char Msg[128]={0};
10. sprintf(Msg,"%d",err);
11. MessageBox(NULL,Msg,"Err",MB_OK);
12. return -1;
13. }
14. long ret = Pt->Add(1,2);
15. CoUninitialize();
16. return 0;
17. }

int impl2()
{
CoInitialize(NULL);
IMyComPtr Pt ;
if (!SUCCEEDED(Pt.CreateInstance(__uuidof(MyCom))))
{
DWORD err;
err = GetLastError();
char Msg[128]={0};
sprintf(Msg,"%d",err);
MessageBox(NULL,Msg,"Err",MB_OK);
return -1;
}
long ret = Pt->Add(1,2);
CoUninitialize();
return 0;
}

第四种方法：

Cpp代码  

1. int impl3()
2. {
3. CoInitialize(NULL);
4. IMyComPtr Pt(__uuidof(MyCom)) ;
5. long ret = Pt->Add(1,2);
6. CoUninitialize();
7. return 0;
8. }

int impl3()
{
CoInitialize(NULL);
IMyComPtr Pt(__uuidof(MyCom)) ;
long ret = Pt->Add(1,2);
CoUninitialize();
return 0;
}

第五种方法：

Cpp代码  

1. int impl4()
2. {
3. CoInitialize(NULL);
4. IMyCom * pMyCom=NULL;
5. CLSID clsid;
6. IID iid;
7. HRESULT hr = CLSIDFromString(OLESTR("{92e83a37-399a-47b1-bf6c-0ab052650cfe}"),&clsid);
8. if(NOERROR != hr){
9. MessageBox    (NULL,"ErrCLSIDFromString","ErrCLSIDFromString",MB_OK);
10. return -1;
11. }
12. HRESULT hriid = IIDFromString(OLESTR("{103b4c6e-3d3e-4e38-ab50-b9348465fc13}"),&iid);
13. if(S_OK != hriid){
14. MessageBox(NULL,"ErrIIDFromString","ErrIIDFromString",MB_OK);
15. return -1;
16. }
17. if (!SUCCEEDED(::CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,iid,(void**)&pMyCom)))
18. {
19. DWORD err;
20. err = GetLastError();
21. char Msg[128]={0};
22. sprintf(Msg,"%d",err);
23. MessageBox(NULL,Msg,"Err",MB_OK);
24. return -1;
25. }
26. long ret;
27. ret = pMyCom->Add(1,2);
28. CoUninitialize();
29. return 0;
30. }

int impl4()
{CoInitialize(NULL);IMyCom * pMyCom=NULL;CLSID clsid;IID iid;HRESULT hr = CLSIDFromString(OLESTR("{92e83a37-399a-47b1-bf6c-0ab052650cfe}"),&clsid);if(NOERROR != hr){MessageBox    (NULL,"ErrCLSIDFromString","ErrCLSIDFromString",MB_OK);
return -1;
}HRESULT hriid = IIDFromString(OLESTR("{103b4c6e-3d3e-4e38-ab50-b9348465fc13}"),&iid);
if(S_OK != hriid){MessageBox(NULL,"ErrIIDFromString","ErrIIDFromString",MB_OK);return -1;
}if (!SUCCEEDED(::CoCreateInstance(clsid,NULL,CLSCTX_INPROC_SERVER,iid,(void**)&pMyCom)))
{DWORD err;err = GetLastError();char Msg[128]={0};sprintf(Msg,"%d",err);MessageBox(NULL,Msg,"Err",MB_OK);return -1;
}long ret;
ret = pMyCom->Add(1,2);CoUninitialize();
return 0;
}

int main(int argc, char* argv[])
{
return impl0();
}