实现
了
§2
和
§3
的
简单
的程序,
这
些程序并不是完全意
义
上的
COM
程序。
§2 —— IFACE.CPP
代
码
清
单
:
//
//Iface.cpp
//
//
#include
<iostream.h>
#include
<objbase.h>
//Define interface
void
trace(
const
char
* pMsg) {cout << pMsg << endl ;}
interface IX
{
virtual
void
__stdcall
Fx1() = 0;
virtual
void
__stdcall
Fx2() = 0;
};
interface IY
{
virtual
void
__stdcall
Fy1() = 0;
virtual
void
__stdcall
Fy2() = 0;
};
class
CA :
public
IX,
public
IY
{
public
:
virtual
void
__stdcall
Fx1() {cout <<
"CA::Fx1"
<< endl ;}
virtual
void
__stdcall
Fx2() {cout <<
"CA::Fx2"
<< endl ;}
virtual
void
__stdcall
Fy1() {cout <<
"CA::Fy1"
<< endl ;}
virtual
void
__stdcall
Fy2() {cout <<
"CA::Fy2"
<< endl ;}
};
int
main()
{
trace(
"Client:Create an instance of the component."
);
CA* pA =
new
CA;
IX* pIX = pA;
trace(
"Client:Use the IX interface."
);
pIX->Fx1();
pIX->Fx2();
IY* pIY = pA;
trace(
"Client:Use the IY interface."
);
pIY->Fy1();
pIY->Fy2();
trace(
"Client:Delete the component."
);
delete
pA;
return
0;
}
§3 —— IUnknown.CPP代码清单:
//
//IUnkown.cpp
//
//
#include <iostream.h>
#include <objbase.h>
void trace(const char * msg) {cout << msg << endl ;}
//Interface
interface IX : IUnknown
{
virtual void __stdcall Fx() = 0;
};
interface IY : IUnknown
{
virtual void __stdcall Fy() = 0;
};
interface IZ : IUnknown
{
virtual void __stdcall Fz() = 0;
};
//Forward references for GUIDs
extern const IID IID_IX;
extern const IID IID_IY;
extern const IID IID_IZ;
//
//Component
//
class CA : public IX, public IY
{
//IUnknown implementation
virtual HRESULT __stdcall QueryInterface(const IID& iid, void** ppv);
virtual ULONG __stdcall AddRef() {return 0;}
virtual ULONG __stdcall Release() {return 0;}
//Interface IX implementation
virtual void __stdcall Fx() {cout << "Fx" << endl ;}
//Interface IY implementation
virtual void __stdcall Fy() {cout << "Fy" << endl ;}
};
HRESULT __stdcall CA::QueryInterface(const IID& iid, void** ppv)
{
if(iid == IID_IUnknown)
{
trace("QueryInterface:Return pointer to IUnknown.");
*ppv = static_cast< IX* >(this);
}
else if(iid == IID_IX)
{
trace("QueryInterface:Return pointer to IX.");
*ppv = static_cast< IX* >(this);
}
else if(iid == IID_IY)
{
trace("QueryInterface:Return pointer to IY.");
*ppv = static_cast< IY* >(this);
}
else
{
trace("QueryInterface:Interface not supported.");
*ppv = NULL;
return E_NOINTERFACE;
}
reinterpret_cast< IUnknown* >(*ppv)->AddRef();
return S_OK;
}
//
//Creation function
//
IUnknown* CreateInstance()
{
IUnknown* pI = static_cast< IX* >(new CA);
pI->AddRef();
return pI;
}
//
//IIDs
//
//{32bb8320-b41b-11cf-a6bb-0080c7b2d682}
static const IID IID_IX =
{0x32bb8320, 0xb41b, 0x11cf,
{0xa6, 0xbb, 0x0, 0x80, 0xc7, 0xb2, 0xd6, 0x82}};
//{32bb8321-b41b-11cf-a6bb-0080c7b2d682}
static const IID IID_IY =
{0x32bb8321, 0xb41b, 0x11cf,
{0xa6, 0xbb, 0x0, 0x80, 0xc7, 0xb2, 0xd6, 0x82}};
//{32bb8322-b41b-11cf-a6bb-0080c7b2d682}
static const IID IID_IZ =
{0x32bb8322, 0xb41b, 0x11cf,
{0xa6, 0xbb, 0x0, 0x80, 0xc7, 0xb2, 0xd6, 0x82}};
//
//Client
//
int main()
{
HRESULT hr;
trace("Client:Get an IUnknown pointer.");
IUnknown* pIUnknown = CreateInstance();
trace("Client:Get Interface IX.");
IX* pIX = NULL;
hr = pIUnknown->QueryInterface(IID_IX,(void**)&pIX);
if(SUCCEEDED(hr))
{
trace("Client:Succeeded getting IX.");
pIX->Fx(); //Use interface IX
}
trace("Client:Get Interface IY.");
IY* pIY = NULL;
hr = pIUnknown->QueryInterface(IID_IY,(void**)&pIY);
if(SUCCEEDED(hr))
{
trace("Client:Succeeded getting IY.");
pIY->Fy(); //Use interface IY
}
trace("Client:Get Interface IZ.");
IZ* pIZ = NULL;
hr = pIUnknown->QueryInterface(IID_IZ,(void**)&pIZ);
if(SUCCEEDED(hr))
{
trace("Client:Succeeded getting IZ.");
pIZ->Fz();
}
else
{
trace("Client:Could not get interface IZ.");
}
trace("Client:Get interface IY from interface IX.");
IY* pIYfromIX = NULL;
hr = pIX->QueryInterface(IID_IY, (void**)&pIYfromIX);
if(SUCCEEDED(hr))
{
trace("Client:Succeeded getting IY.");
pIYfromIX->Fy();
}
trace("Client:Get interface IUnknown from IY.");
IUnknown* pIUknownFromIY = NULL;
hr = pIY->QueryInterface(IID_IUnknown, (void**)&pIUknownFromIY);
if(SUCCEEDED(hr))
{
cout << "equal?" ;
if(pIUknownFromIY == pIUnknown)
{
cout << "Yes." << endl;
}
else
{
cout << "No." << endl;
}
}
//Delete the component
delete pIUnknown;
return 0;
}
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