一段能夠下載文件的源代碼

// 在工程中加入 Urlmon.lib
//---------------------------------------------------------------------------
#include <vcl.h>
#include <windows.h>
#include <Urlmon.h>
#pragma hdrstop
#include "Unit1.h"
//---------------------------------------------------------------------------
cImpMonikerCallback objImpCallback;
//---------------------------------------------------------------------------
#pragma argsused
WINAPI WinMain(HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int nCmdShow)
{
　 LPUNKNOWN pCaller;
　　pCaller = NULL;
　　DWORD dwResv = 0;
　　objImpCallback.lpfnCB = (IBindStatusCallback *)&objImpCallback;
　　HRESULT hRet=URLDownloadToFile(pCaller,"http://127.0.0.1:30000/download/icon.zip","d:\\temp\\icon.zip",dwResv,objImpCallback.lpfnCB);
　 if(hRet==S_OK)
　　 MessageBox(NULL,"成功下載文件","",MB_OK);
　 return 0;
}
//---------------------------------------------------------------------------
cImpMonikerCallback::cImpMonikerCallback()
{
　 m_cRef = 1;
　 m_pbinding = NULL;
};
//---------------------------------------------------------------------------
cImpMonikerCallback::~cImpMonikerCallback()
{
　 if(m_pbinding)
　　 m_pbinding->Release();
};
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::QueryInterface(REFIID riid,void ** ppv)
{
　 *ppv = NULL;
　 if (riid==IID_IUnknown &brvbar;&brvbar; riid==IID_IBindStatusCallback)
　 {
　　 *ppv = this;
　　 AddRef();
　　 return S_OK;
　 }
　 return E_NOINTERFACE;
};
//---------------------------------------------------------------------------
STDMETHODIMP_(ULONG) cImpMonikerCallback::AddRef()
{
　 return m_cRef++;
}
//---------------------------------------------------------------------------
STDMETHODIMP_(ULONG) cImpMonikerCallback::Release()
{
　 if(--m_cRef==0)
　 {
　　 delete this;
　　 return 0;
　 }
　 return m_cRef;
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::GetBindInfo(DWORD* pgrfBINDF, BINDINFO* pbindinfo)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnStartBinding(DWORD grfBSCOption, IBinding* pbinding)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::GetPriority(LONG* pnPriority)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnProgress(ULONG ulProgress, ULONG ulProgressMax,ULONG ulStatusCode, LPCWSTR szStatusText)
{
　 return(NOERROR);
};
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnDataAvailable(DWORD grfBSCF, DWORD dwSize, FORMATETC *pfmtetc,STGMEDIUM* pstgmed)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnObjectAvailable(REFIID riid, IUnknown* punk)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnLowResource(DWORD dwReserved)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
STDMETHODIMP cImpMonikerCallback::OnStopBinding(HRESULT hrStatus, LPCWSTR szText)
{
　 return(NOERROR);
}
//---------------------------------------------------------------------------
///////////////////////////////////////////////////////////////////////
///////////////////////////////////////////////////////////////////////
class cImpMonikerCallback:public IBindStatusCallback
{
　 DWORD m_cRef;
　 IBinding* m_pbinding;
public:
　　　　 cImpMonikerCallback();
　　　　 ~cImpMonikerCallback();
　　　　 STDMETHODIMP QueryInterface(REFIID riid,void ** ppv);
　　　　 STDMETHODIMP_(ULONG) AddRef();//　　{ return m_cRef++; }
　 STDMETHODIMP_(ULONG) Release();
　　　　 STDMETHODIMP GetBindInfo(DWORD* pgrfBINDF, BINDINFO* pbindinfo);
　　　　 STDMETHODIMP OnStartBinding(DWORD grfBSCOption, IBinding* pbinding);
　　　　 STDMETHODIMP GetPriority(LONG* pnPriority);
　　　　 STDMETHODIMP OnProgress(ULONG ulProgress, ULONG ulProgressMax,ULONG ulStatusCode, LPCWSTR szStatusText);
　　　　 STDMETHODIMP OnDataAvailable(DWORD grfBSCF, DWORD dwSize, FORMATETC *pfmtetc,STGMEDIUM* pstgmed);
　　　　 STDMETHODIMP OnObjectAvailable(REFIID riid, IUnknown* punk);
　　　　 STDMETHODIMP OnLowResource(DWORD dwReserved);
　　　　 STDMETHODIMP OnStopBinding(HRESULT hrStatus, LPCWSTR szText);
　　　　 LPBINDSTATUSCALLBACK lpfnCB;
　　　　 PSTR sURL;
　　　　 PSTR sFile;
　 char cSysDir[MAX_PATH];
　 DWORD dwPlatform;
};