www.gusucode.com > VC++ 使用ADO操作ACCESS数据库中长二进制数据-源码程序 > VC++ 使用ADO操作ACCESS数据库中长二进制数据-源码程序/code/DemoDlg.cpp
// DemoDlg.cpp : implementation file // Download by http://www.NewXing.com #include "stdafx.h" #include "Demo.h" #include "DemoDlg.h" #include "FolderDialog.h" #include <afxdlgs.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() ///////////////////////////////////////////////////////////////////////////// // CDemoDlg dialog CDemoDlg::CDemoDlg(CWnd* pParent /*=NULL*/) : CDialog(CDemoDlg::IDD, pParent) { //{{AFX_DATA_INIT(CDemoDlg) //}}AFX_DATA_INIT // Note that LoadIcon does not require a subsequent DestroyIcon in Win32 m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME); if (!SUCCEEDED(m_pConnection.CreateInstance(__uuidof(Connection)))) { m_pConnection = NULL; TRACE(_T("Database CreateInstance failed")); } if (!SUCCEEDED(m_pRecordset.CreateInstance(__uuidof(Recordset)))) { m_pRecordset = NULL; TRACE(_T("Recordset CreateInstance Failed!")); } //打开数据库 CString strConnect = _T("Provider=Microsoft.Jet.OLEDB.4.0;Data Source= Demo.mdb"); if (!OpenDatabase(strConnect)) { AfxMessageBox(_T("数据库打开失败。")); return; } //打开记录集 CString strSource = _T("SELECT * FROM DemoTable"); if (!OpenRecordset(strSource)) { AfxMessageBox(_T("记录集打开失败。")); return; } } CDemoDlg::~CDemoDlg() { m_pRecordset->Close(); m_pConnection->Close(); } void CDemoDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(CDemoDlg) //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(CDemoDlg, CDialog) //{{AFX_MSG_MAP(CDemoDlg) ON_WM_SYSCOMMAND() ON_WM_PAINT() ON_WM_QUERYDRAGICON() ON_BN_CLICKED(IDC_WRITE, OnWrite) ON_BN_CLICKED(IDC_MOVENEXT, OnMoveNext) ON_BN_CLICKED(IDC_MOVWPREV, OnMovePrev) ON_BN_CLICKED(IDC_READ, OnRead) //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CDemoDlg message handlers BOOL CDemoDlg::OnInitDialog() { CDialog::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 //读取记录集 if (m_pRecordset->BOF && m_pRecordset->adoEOF) { return FALSE; } m_pRecordset->MoveFirst(); _variant_t varName; CString strName = _T(""); varName = m_pRecordset->GetCollect(_variant_t(_T("NAME"))); if (varName.vt != VT_NULL) { strName = varName.bstrVal; } else { strName = _T(""); } SetDlgItemText(IDC_NAME, strName); return TRUE; } void CDemoDlg::OnSysCommand(UINT nID, LPARAM lParam) { if ((nID & 0xFFF0) == IDM_ABOUTBOX) { CAboutDlg dlgAbout; dlgAbout.DoModal(); } else { CDialog::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 CDemoDlg::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 { CDialog::OnPaint(); } } // The system calls this to obtain the cursor to display while the user drags // the minimized window. HCURSOR CDemoDlg::OnQueryDragIcon() { return (HCURSOR) m_hIcon; } BOOL CDemoDlg::OpenDatabase(LPCTSTR lpszConnect, long nOptions) { ASSERT(m_pConnection != NULL); ASSERT(lpszConnect != NULL); ASSERT(AfxIsValidString(lpszConnect)); //打开数据库连接 try { return SUCCEEDED(m_pConnection->Open(_bstr_t(lpszConnect), _T(""), _T(""), nOptions)); } catch (_com_error& e) { TRACE(_T("%s\n"), e.ErrorMessage()); return FALSE; } } BOOL CDemoDlg::CloseDatabase() { ASSERT(m_pConnection != NULL); //关闭数据库连接 try { if (m_pConnection->State & adStateOpen) { return SUCCEEDED(m_pConnection->Close()); } else { return TRUE; } } catch (_com_error& e) { TRACE(_T("%s\n"), e.ErrorMessage()); return FALSE; } } BOOL CDemoDlg::OpenRecordset(LPCTSTR lpszSource, long nCursorType, long nLockType, long nOptions) { ASSERT(m_pConnection != NULL); ASSERT(m_pRecordset != NULL); ASSERT(lpszSource != NULL); ASSERT(AfxIsValidString(lpszSource)); //打开记录集 try { return (SUCCEEDED(m_pRecordset->Open(_variant_t(lpszSource), m_pConnection.GetInterfacePtr(), (CursorTypeEnum)nCursorType, (LockTypeEnum)nLockType, nOptions))); } catch(_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return FALSE; } } BOOL CDemoDlg::CloseRecordset() { ASSERT(m_pRecordset != NULL); //关闭记录集 try { if (m_pRecordset->State & adStateOpen) { return SUCCEEDED(m_pRecordset->Close()); } else { return TRUE; } } catch (_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return FALSE; } } void CDemoDlg::OnWrite() { //创建文件对话框 CString strFilter="二进制文件(*.*)|*.*||"; CFileDialog dlg(TRUE, NULL, NULL, OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT, strFilter); dlg.m_ofn.lpstrTitle = _T("打开二进制文件"); if(dlg.DoModal() == IDOK) { //获得文件路径 CString strFileName = dlg.GetPathName(); //打开文件 CFile file; if (!file.Open(strFileName, CFile::modeRead)) { AfxMessageBox(_T("文件打开失败。"), MB_ICONINFORMATION); return; } //获得文件名 CString strName = file.GetFileTitle(); //获得数据大小 UINT nLength = file.GetLength(); //分配缓冲区 BYTE* pChunk = new BYTE[nLength]; //读文件 file.Read(pChunk, nLength); //写数据库 m_pRecordset->AddNew(); m_pRecordset->PutCollect(_variant_t(_T("NAME")), _variant_t(strName)); SetFieldChunk(_T("Data"), pChunk, nLength); m_pRecordset->Update(); m_pRecordset->MoveLast(); //释放缓冲区 delete []pChunk; //关闭文件 file.Close(); //刷新 SetDlgItemText(IDC_NAME, strName); AfxMessageBox(_T("文件写入完成。")); } } void CDemoDlg::OnRead() { if (!(m_pRecordset->State & adStateOpen)) { AfxMessageBox((_T("记录集未打开。"))); return; } //判断记录集是否为空 if (m_pRecordset->BOF && m_pRecordset->adoEOF) { return; } //创建目录对话框 CFolderDialog dlg(BIF_RETURNONLYFSDIRS | BIF_NEWDIALOGSTYLE | BIF_EDITBOX); if (dlg.DoModal() == IDOK) { //获得文件路径 CString strFolderName = dlg.GetPathName(); //读数据库 variant_t varName; CString strName = _T(""); varName = m_pRecordset->GetCollect(_variant_t(_T("NAME"))); if (varName.vt != VT_NULL) { strName = varName.bstrVal; } else { strName = _T(""); } //打开文件 CFile file; CString strFileName = _T(""); strFileName.Format(_T("%s\\%s"), strFolderName, strName); if (!file.Open(strFileName, CFile::modeCreate | CFile::modeWrite)) { AfxMessageBox(_T("文件打开失败。"), MB_ICONINFORMATION); return; } //获得数据大小 UINT nLength = m_pRecordset->Fields->GetItem(_variant_t(_T("Data")))->ActualSize; //分配缓冲区 BYTE* pChunk = new BYTE[nLength]; //读数据库 GetFieldChunk(_T("Data"), pChunk, nLength); //写文件 file.Write(pChunk, nLength); //释放缓冲区 delete []pChunk; //关闭文件 file.Close(); AfxMessageBox(_T("文件读出完成。")); } } void CDemoDlg::OnMoveNext() { if (!(m_pRecordset->State & adStateOpen)) { AfxMessageBox((_T("记录集未打开。"))); return; } //判断记录集是否为空 if (m_pRecordset->BOF && m_pRecordset->adoEOF) { return; } //移动记录集 try { m_pRecordset->MoveNext(); if (m_pRecordset->adoEOF) { m_pRecordset->MoveFirst(); } } catch(_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return; } //读取记录集 _variant_t varName; CString strName = _T(""); varName = m_pRecordset->GetCollect(_variant_t(_T("NAME"))); if (varName.vt != VT_NULL) { strName = varName.bstrVal; } else { strName = _T(""); } //刷新 SetDlgItemText(IDC_NAME, strName); } void CDemoDlg::OnMovePrev() { if (!(m_pRecordset->State & adStateOpen)) { AfxMessageBox((_T("记录集未打开。"))); return; } //判断记录集是否为空 if (m_pRecordset->BOF && m_pRecordset->adoEOF) { return; } //移动记录集 try { m_pRecordset->MovePrevious(); if (m_pRecordset->BOF) { m_pRecordset->MoveLast(); } } catch(_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return; } //读取记录集 _variant_t varName; CString strName = _T(""); varName = m_pRecordset->GetCollect(_variant_t(_T("NAME"))); if (varName.vt != VT_NULL) { strName = varName.bstrVal; } else { strName = _T(""); } //刷新 SetDlgItemText(IDC_NAME, strName); } BOOL CDemoDlg::SetFieldChunk(LPCTSTR lpszName, LPVOID pChunk, long nChunkSize) { ASSERT(m_pRecordset != NULL); ASSERT(lpszName != NULL); ASSERT(AfxIsValidString(lpszName)); ASSERT(pChunk != NULL); ASSERT(nChunkSize > 0); ASSERT(AfxIsValidAddress(pChunk, nChunkSize)); SAFEARRAY* pSafeArray = NULL; SAFEARRAYBOUND rgsabound[1]; rgsabound[0].lLbound = 0; rgsabound[0].cElements = nChunkSize; pSafeArray = SafeArrayCreate(VT_UI1, 1, rgsabound); for (long n = 0; n < nChunkSize; n++) { BYTE* pData = &(((BYTE*)pChunk)[n]); SafeArrayPutElement(pSafeArray, &n, pData); } _variant_t vtChunk; vtChunk.vt = VT_ARRAY | VT_UI1; vtChunk.parray = pSafeArray; try { return SUCCEEDED(m_pRecordset->Fields->GetItem(_variant_t(lpszName))->AppendChunk(vtChunk)); } catch (_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return FALSE; } } int CDemoDlg::GetFieldChunk(LPCTSTR lpszName, LPVOID pChunk, long nChunkSize) { ASSERT(m_pRecordset != NULL); ASSERT(lpszName != NULL); ASSERT(AfxIsValidString(lpszName)); ASSERT(pChunk != NULL); ASSERT(nChunkSize > 0); ASSERT(AfxIsValidAddress(pChunk, nChunkSize)); int nActualSize = m_pRecordset->Fields->GetItem(_variant_t(lpszName))->ActualSize; if (nActualSize < 0) { return -1; } int nSize = min(nActualSize, nChunkSize); _variant_t vtChunk; try { vtChunk = m_pRecordset->Fields->GetItem(_variant_t(lpszName))->GetChunk(nSize); } catch (_com_error e) { TRACE(_T("%s\n"), e.ErrorMessage()); return -1; } if (vtChunk.vt == (VT_ARRAY | VT_UI1)) { BYTE* p =new BYTE; for (long n = 0; n < nSize; n++) { ::SafeArrayGetElement(vtChunk.parray, &n, p); ((BYTE*)pChunk)[n] = *p; } delete p; } return nSize; }