使用 CInternetSession 封装多线程 http 文件下载（源码）

// DownloadDlg.cpp : implementation file // #include "stdafx.h" #include "Download.h" #include "DownloadDlg.h" #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif ///////////////////////////////////////////////////////////////////////////// // CAboutDlg dialog used for App About class CAboutDlg : public CDialog { public: CAboutDlg(); // Dialog Data //{{AFX_DATA(CAboutDlg) enum { IDD = IDD_ABOUTBOX }; //}}AFX_DATA // ClassWizard generated virtual function overrides //{{AFX_VIRTUAL(CAboutDlg) protected: virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support //}}AFX_VIRTUAL // Implementation protected: //{{AFX_MSG(CAboutDlg) //}}AFX_MSG DECLARE_MESSAGE_MAP() }; CAboutDlg::CAboutDlg() : CDialog(CAboutDlg::IDD) { //{{AFX_DATA_INIT(CAboutDlg) //}}AFX_DATA_INIT } void CAboutDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(CAboutDlg) //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(CAboutDlg, CDialog) //{{AFX_MSG_MAP(CAboutDlg) // No message handlers //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CDownloadDlg dialog CDownloadDlg::CDownloadDlg(CWnd* pParent /*=NULL*/) : MainDlgBase(CDownloadDlg::IDD, pParent) { //{{AFX_DATA_INIT(CDownloadDlg) m_strURL = _T(""); m_strStatus = _T(""); m_strAverage = _T(""); m_strCurrent = _T(""); m_nSelTask = -1; m_nDownload = 0; m_strTotal = _T(""); //}}AFX_DATA_INIT // Note that LoadIcon does not require a subsequent DestroyIcon in Win32 m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME); } void CDownloadDlg::DoDataExchange(CDataExchange* pDX) { MainDlgBase::DoDataExchange(pDX); //{{AFX_DATA_MAP(CDownloadDlg) DDX_Control(pDX, IDC_PROGRESS, m_Progress); DDX_Text(pDX, IDC_FILE_URL, m_strURL); DDX_Text(pDX, IDC_STATUS, m_strStatus); DDX_Text(pDX, IDC_AVERAGE_SPEED, m_strAverage); DDX_Text(pDX, IDC_CURRENT_SPEED, m_strCurrent); DDX_LBIndex(pDX, IDC_TASK_LIST, m_nSelTask); DDX_Text(pDX, IDC_DOWNLOAD_BYTE, m_nDownload); DDX_Text(pDX, IDC_TOTAL_BYTE, m_strTotal); //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(CDownloadDlg, MainDlgBase) //{{AFX_MSG_MAP(CDownloadDlg) ON_WM_SYSCOMMAND() ON_WM_PAINT() ON_WM_QUERYDRAGICON() ON_LBN_SELCHANGE(IDC_TASK_LIST, OnSelchangeTaskList) ON_LBN_DBLCLK(IDC_TASK_LIST, OnDblclkTaskList) //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CDownloadDlg message handlers BOOL CDownloadDlg::OnInitDialog() { MainDlgBase::OnInitDialog(); // Add "About..." menu item to system menu. // IDM_ABOUTBOX must be in the system command range. ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX); ASSERT(IDM_ABOUTBOX < 0xF000); CMenu* pSysMenu = GetSystemMenu(FALSE); if (pSysMenu != NULL) { CString strAboutMenu; strAboutMenu.LoadString(IDS_ABOUTBOX); if (!strAboutMenu.IsEmpty()) { pSysMenu->AppendMenu(MF_SEPARATOR); pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu); } } // Set the icon for this dialog. The framework does this automatically // when the application's main window is not a dialog SetIcon(m_hIcon, TRUE); // Set big icon SetIcon(m_hIcon, FALSE); // Set small icon m_Progress.SetRange (0, 100) ; UpdateShowInfo() ; return TRUE; // return TRUE unless you set the focus to a control } void CDownloadDlg::OnSysCommand(UINT nID, LPARAM lParam) { if ((nID & 0xFFF0) == IDM_ABOUTBOX) { CAboutDlg dlgAbout; dlgAbout.DoModal(); } else { MainDlgBase::OnSysCommand(nID, lParam); } } // If you add a minimize button to your dialog, you will need the code below // to draw the icon. For MFC applications using the document/view model, // this is automatically done for you by the framework. void CDownloadDlg::OnPaint() { if (IsIconic()) { CPaintDC dc(this); // device context for painting SendMessage(WM_ICONERASEBKGND, (WPARAM) dc.GetSafeHdc(), 0); // Center icon in client rectangle int cxIcon = GetSystemMetrics(SM_CXICON); int cyIcon = GetSystemMetrics(SM_CYICON); CRect rect; GetClientRect(&rect); int x = (rect.Width() - cxIcon + 1) / 2; int y = (rect.Height() - cyIcon + 1) / 2; // Draw the icon dc.DrawIcon(x, y, m_hIcon); } else { MainDlgBase::OnPaint(); } } // The system calls this to obtain the cursor to display while the user drags // the minimized window. HCURSOR CDownloadDlg::OnQueryDragIcon() { return (HCURSOR) m_hIcon; } void CDownloadDlg::OnOK() { UpdateData() ; ((CEdit*)GetDlgItem(IDC_FILE_URL))->SetSel(0,-1) ; GetDlgItem(IDC_FILE_URL)->SetFocus() ; if (m_strURL.IsEmpty()) return ; if (FindTask(m_strURL)) { AfxMessageBox (_T("The URL task has exist.")) ; return ; } DownloadFile(m_strURL) ; } BOOL CDownloadDlg::DownloadFile_OnCheckTime (CString strFileURL, CString strTime) { TaskPack * p = new TaskPack ; p->strURL = strFileURL ; m_Task.push_back (p) ; CListBox * pList = (CListBox*)GetDlgItem(IDC_TASK_LIST) ; pList->SetCurSel (pList->AddString (strFileURL)) ; return TRUE ; } void CDownloadDlg::DownloadFile_OnFinished (CString strFileURL, char* pBuffer, int nLength) { TaskPack * p = FindTask (strFileURL) ; p->nDownload = p->nTotal = nLength ; p->strStatus = _T("Finished") ; p->tickEnd = ::GetTickCount() ; ASSERT(!p->pContext) ; p->pContext = new BYTE[nLength+8] ; ZeroMemory (p->pContext, nLength+8) ; CopyMemory (p->pContext, pBuffer, nLength) ; UpdateShowInfo() ; IMFlashWindow(GetSafeHwnd()) ; } void CDownloadDlg::DownloadFile_OnProgress (CString strFileURL, int nNow, int nTotal) { TaskPack * p = FindTask (strFileURL) ; p->nDownDelta = nNow - p->nDownload ; p->tickDelta = GetTickCount() - p->tickEnd ; p->nDownload = nNow ; p->nTotal = nTotal ; p->tickEnd = GetTickCount() ; UpdateShowInfo() ; } void CDownloadDlg::DownloadFile_OnError (CString strFileURL) { TaskPack * p = FindTask (strFileURL) ; if (!p) return ; p->strStatus = _T("Error") ; UpdateShowInfo() ; } void CDownloadDlg::OnSelchangeTaskList() { UpdateShowInfo() ; } void CDownloadDlg::UpdateShowInfo() { UpdateData() ; if (m_nSelTask == -1) { m_nDownload = 0 ; m_strStatus = m_strCurrent = m_strAverage = _T("---") ; m_Progress.SetPos(0) ; UpdateData(FALSE) ; return ; } TaskPack * p = m_Task[m_nSelTask] ; // set progress int nPos = 0 ; if (p->nTotal) nPos = p->nDownload * 100 / p->nTotal ; m_Progress.SetPos (nPos) ; m_strStatus = p->strStatus ; m_nDownload = p->nDownload ; if (p->nTotal) { m_strTotal.Format (_T("%d"), p->nTotal) ; } else { m_strTotal = _T("unknown") ; } if (m_strStatus == _T("Downloading")) { int n = p->tickDelta ? (p->nDownDelta / p->tickDelta) : 9999 ; m_strCurrent.Format (_T("%d Kb/s"), n) ; } else { m_strCurrent = _T("---") ; } DWORD dw = (p->tickEnd - p->tickStart) ; int n = dw ? (p->nDownload / dw) : 9999 ; m_strAverage.Format (_T("%d Kb/s"), n) ; UpdateData(FALSE) ; } void CDownloadDlg::OnDblclkTaskList() { UpdateData() ; if (m_nSelTask != -1) { TaskPack * p = m_Task[m_nSelTask] ; if (p->pContext) { CFileDialog dlg (FALSE) ; if (dlg.DoModal() == IDOK) { CFile outFile (dlg.GetPathName(), CFile::modeCreate|CFile::modeReadWrite) ; outFile.Write (p->pCo