URLDownloadToFile 수행시 진행상황 파악하기

URLDownloadToFile 함수를 이용하여 URL 로부터 다운을 받을때 이 함수만을 단독으로 이용하면 받는동안 진행상황을 파악할 수 없으며 다운로드가 종료될때까지 다른 작업을 수행 할 수 없다.

진행상황을 파악하기 위해서는 CallBack 함수를 이용해야 하고, 진행중 다른 작업을 하려면 Thread로 동작을 하거나 Application에 다른 작업을 하도록 해주어야 한다.

GMPmp3 의 업그레이드 버전인 v2 를 만들기 위해 이 방법을 사용하였다.

진행 상황을 파악하기 위한 CallBack 함수는 IBindStatusCallback 인터페이스를 상속 받아 구현한다.
함수 중 OnProgress 함수가 진행 중 계속 호출되어 이 함수내에 다운로드 진행상황을 처리해주면 된다.

//--------------------------------------------------------------------------- // Header #include <vcl.h> #include <windows.h> #include <UrlMon.h> #include <UrlMon.hpp> #pragma comment(lib,"urlmon.lib") #pragma comment(lib,"WinInet.lib") class TCallback : public IBindStatusCallback { DWORD m_cRef; private: STDMETHODIMP QueryInterface(REFIID riid,void **ppv); STDMETHODIMP_(ULONG) AddRef(); STDMETHODIMP_(ULONG) Release(); STDMETHODIMP GetBindInfo(DWORD *grfBINDF,BINDINFO *bindinfo); STDMETHODIMP GetPriority(LONG *nPriority); STDMETHODIMP OnDataAvailable(DWORD grfBSCF,DWORD dwSize, FORMATETC *formatetc,STGMEDIUM *stgmed); STDMETHODIMP OnLowResource(DWORD reserved); STDMETHODIMP OnObjectAvailable(REFIID iid,IUnknown *punk); STDMETHODIMP OnStartBinding(DWORD dwReserved,IBinding *pib); STDMETHODIMP OnStopBinding(HRESULT hresult,LPCWSTR szError); STDMETHODIMP OnProgress(ULONG ulProgress, ULONG ulProgressMax, ULONG ulStatusCode, LPCWSTR szStatusText); public: TfrmDownload* frmDown; // 진행상황을 표시해줄 Form 포인터 TCallback() {m_cRef = 1;}; }; //--------------------------------------------------------------------------- // Source STDMETHODIMP TCallback::QueryInterface(REFIID riid,void **ppv) { *ppv = NULL; if (riid==IID_IUnknown || riid==IID_IBindStatusCallback) { *ppv = this; AddRef(); return S_OK; } return E_NOINTERFACE; } STDMETHODIMP_(ULONG) TCallback::AddRef() { return m_cRef++; } STDMETHODIMP_(ULONG) TCallback::Release() { if(--m_cRef==0) { delete this; return 0; } return m_cRef; } STDMETHODIMP TCallback::GetBindInfo(DWORD *grfBINDF,BINDINFO *bindinfo) { return E_NOTIMPL; } STDMETHODIMP TCallback::GetPriority(LONG *nPriority) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnDataAvailable(DWORD grfBSCF,DWORD dwSize, FORMATETC *formatetc,STGMEDIUM *stgmed) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnLowResource(DWORD reserved) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnObjectAvailable(REFIID iid,IUnknown *punk) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnStartBinding(DWORD dwReserved,IBinding *pib) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnStopBinding(HRESULT hresult,LPCWSTR szError) { return E_NOTIMPL; } STDMETHODIMP TCallback::OnProgress(ULONG ulProgress, ULONG ulProgressMax, ULONG ulStatusCode, LPCWSTR szStatusText) { AnsiString Status; switch (ulStatusCode) { case BINDSTATUS_FINDINGRESOURCE : Status = "Finding resource " + AnsiString(szStatusText); break; case BINDSTATUS_CONNECTING : Status = "Connecting to " + AnsiString(szStatusText); break; case BINDSTATUS_REDIRECTING : Status = "Redirecting..."; break; case BINDSTATUS_BEGINDOWNLOADDATA : Status = "Start to download " + AnsiString(szStatusText); break; case BINDSTATUS_DOWNLOADINGDATA : Status = "Downloading..."; break; case BINDSTATUS_ENDDOWNLOADDATA : Status = "Complete downloading " + AnsiString(szStatusText); break; case BINDSTATUS_BEGINDOWNLOADCOMPONENTS : Status = "Start to download components"; break; case BINDSTATUS_INSTALLINGCOMPONENTS : Status = "Installing components..." ; break; case BINDSTATUS_ENDDOWNLOADCOMPONENTS : Status = "Complete downloading components"; break; case BINDSTATUS_USINGCACHEDCOPY : Status = "Copying form buffer..."; break; case BINDSTATUS_SENDINGREQUEST : Status = "Sending request..."; break; case BINDSTATUS_CLASSIDAVAILABLE : Status = "Class ID is available"; break; case BINDSTATUS_MIMETYPEAVAILABLE : Status = "MIME type is available"; break; case BINDSTATUS_CACHEFILENAMEAVAILABLE : Status = "Cache file name is available"; break; case BINDSTATUS_BEGINSYNCOPERATION : Status = "Start sync operation"; break; case BINDSTATUS_ENDSYNCOPERATION : Status = "Complete sync operation"; break; case BINDSTATUS_BEGINUPLOADDATA : Status = "Start to upload data"; break; case BINDSTATUS_UPLOADINGDATA : Status = "Uploading data"; break; case BINDSTATUS_ENDUPLOADDATA : Status = "Complete Uploading data"; break; case BINDSTATUS_PROTOCOLCLASSID : Status = "Protocol class ID is available"; break; case BINDSTATUS_ENCODING : Status = "Encoding..."; break; case BINDSTATUS_VERIFIEDMIMETYPEAVAILABLE : Status = "Verified MIME is available"; break; case BINDSTATUS_CLASSINSTALLLOCATION : Status = "Class install location"; break; case BINDSTATUS_DECODING : Status = "Decoding..."; break; case BINDSTATUS_LOADINGMIMEHANDLER : Status = "Loading MIME handler"; break; case BINDSTATUS_CONTENTDISPOSITIONATTACH : Status = "Content disposition attach"; break; case BINDSTATUS_FILTERREPORTMIMETYPE : Status = "Filter report MIME type"; break; case BINDSTATUS_CLSIDCANINSTANTIATE : Status = "Clsid can instantiate"; break; case BINDSTATUS_IUNKNOWNAVAILABLE : Status = "Unknown available"; break; case BINDSTATUS_DIRECTBIND : Status = "Direct bind"; break; case BINDSTATUS_RAWMIMETYPE : Status = "MIME type of the resource, before any code sniffing is done"; break; case BINDSTATUS_PROXYDETECTING : Status = "Detecting proxy..."; break; case BINDSTATUS_ACCEPTRANGES : Status = "Valid types of range requests for a resource"; break; default : Status = ""; } // Application에 다른 메세지를 처리하도록 지시 Application->ProcessMessages(); if (ulProgressMax > 0) { // 진행상황을 Progress Bar를 이용하여 표시 double dblRate = ((double)ulProgress / (double)ulProgressMax) * 100.0; frmDown->prgDownload->Min = 0; frmDown->prgDownload->Max = 100; frmDown->prgDownload->Position = static_cast<int>(dblRate); } if (frmDown->IsUserCancel()) return E_ABORT; // Application에 다른 메세지를 처리하도록 지시 Application->ProcessMessages(); return S_OK; } //--------------------------------------------------------------------------- // Caller m_bDownloading = true; Status.frmDown = this; LPUNKNOWN pCaller = NULL; DeleteUrlCacheEntry(m_strURL.c_str()); HRESULT hRet = URLDownloadToFile(pCaller, m_strURL.c_str(), m_strDst.c_str(), 0, &Status); if (hRet == S_OK) { ShowMessage("다운로드 완료!"); } else if (hRet == E_ABORT) { if (m_bUserCancel == true) ShowMessage("다운로드가 취소되었습니다."); else ShowMessage("다운로드 실패!"); } m_bDownloading = false; Close();