00VC++使用ADO实现BLOB二进制大对象数据的存取，VC++读写Access数据库

// ADOBlobDlg.cpp : implementation file // Download by http://www.NewXing.com #include "stdafx.h" #include "ADOBlob.h" #include "ADOBlobDlg.h" #ifdef _DEBUG #define new DEBUG_NEW #undef THIS_FILE static char THIS_FILE[] = __FILE__; #endif extern CADOBlobApp theApp; ///////////////////////////////////////////////////////////////////////////// // 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() ///////////////////////////////////////////////////////////////////////////// // CADOBlobDlg dialog CADOBlobDlg::CADOBlobDlg(CWnd* pParent /*=NULL*/) : CDialog(CADOBlobDlg::IDD, pParent) { //{{AFX_DATA_INIT(CADOBlobDlg) m_UserName = _T(""); m_Old = _T(""); //}}AFX_DATA_INIT // Note that LoadIcon does not require a subsequent DestroyIcon in Win32 m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME); m_bModify = FALSE; m_hPhotoBitmap = NULL; m_pBMPBuffer = NULL; } void CADOBlobDlg::DoDataExchange(CDataExchange* pDX) { CDialog::DoDataExchange(pDX); //{{AFX_DATA_MAP(CADOBlobDlg) DDX_Control(pDX, IDC_DELETEUSER, m_buttonDeleteUser); DDX_Control(pDX, IDC_PREVIOUSUSER, m_buttonPreviousUser); DDX_Control(pDX, IDC_NEXTUSER, m_buttonNextUser); DDX_Control(pDX, IDC_OLD, m_editOld); DDX_Control(pDX, IDC_USERNAME, m_editUserName); DDX_Control(pDX, IDC_SELECTPHOTO, m_buttonSelectPhoto); DDX_Control(pDX, IDC_SAVEINFO, m_buttonSaveInfo); DDX_Text(pDX, IDC_USERNAME, m_UserName); DDX_Text(pDX, IDC_OLD, m_Old); //}}AFX_DATA_MAP } BEGIN_MESSAGE_MAP(CADOBlobDlg, CDialog) //{{AFX_MSG_MAP(CADOBlobDlg) ON_WM_SYSCOMMAND() ON_WM_PAINT() ON_WM_QUERYDRAGICON() ON_BN_CLICKED(IDC_ADDUSER, OnAddUser) ON_EN_CHANGE(IDC_USERNAME, OnChangeUsername) ON_EN_CHANGE(IDC_OLD, OnChangeOld) ON_BN_CLICKED(IDC_SAVEINFO, OnSaveinfo) ON_BN_CLICKED(IDC_SELECTPHOTO, OnSelectphoto) ON_BN_CLICKED(IDC_NEXTUSER, OnNextUser) ON_BN_CLICKED(IDC_PREVIOUSUSER, OnPreviousUser) ON_BN_CLICKED(IDC_DELETEUSER, OnDeleteUser) //}}AFX_MSG_MAP END_MESSAGE_MAP() ///////////////////////////////////////////////////////////////////////////// // CADOBlobDlg message handlers BOOL CADOBlobDlg::OnInitDialog() { CDialog::OnInitDialog(); 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); } } SetIcon(m_hIcon, TRUE); // Set big icon SetIcon(m_hIcon, FALSE); // Set small icon m_bNewUser = FALSE; m_pRecordset.CreateInstance("ADODB.Recordset"); HRESULT hr = m_pRecordset->Open("SELECT * FROM userphoto",_variant_t((IDispatch *)theApp.m_pConnection,true),adOpenDynamic,adLockPessimistic,adCmdText); if(SUCCEEDED(hr)) { ReadData(); } ResetControls(); return TRUE; // return TRUE unless you set the focus to a control } /////////////////////读取记录集当前记录中数据，包括图像数据////////////// void CADOBlobDlg::ReadData() { DestroyPhoto(); ///清除原图像 if(m_pRecordset->adoEOF||m_pRecordset->BOF) { m_UserName.Empty(); m_Old.Empty(); UpdateData(FALSE); return; } long lDataSize = m_pRecordset->GetFields()->GetItem("photo")->ActualSize; if(lDataSize > 0) { _variant_t varBLOB; varBLOB = m_pRecordset->GetFields()->GetItem("photo")->GetChunk(lDataSize); if(varBLOB.vt == (VT_ARRAY | VT_UI1)) { if(m_pBMPBuffer = new char[lDataSize+1]) ///重新分配必要的存储空间 { char *pBuf = NULL; SafeArrayAccessData(varBLOB.parray,(void **)&pBuf); memcpy(m_pBMPBuffer,pBuf,lDataSize); ///复制数据到缓冲区m_pBMPBuffer SafeArrayUnaccessData (varBLOB.parray); m_nFileLen = lDataSize; m_hPhotoBitmap = BufferToHBITMAP(); ///生成BITMAP对象 } } } m_UserName = m_pRecordset->GetCollect("username").bstrVal; m_Old.Format("%d",m_pRecordset->GetCollect("old").lVal); m_editUserName.EnableWindow(); m_editOld.EnableWindow(); m_buttonSelectPhoto.EnableWindow(); m_buttonDeleteUser.EnableWindow(); UpdateData(FALSE); } void CADOBlobDlg::OnSysCommand(UINT nID, LPARAM lParam) { if ((nID & 0xFFF0) == IDM_ABOUTBOX) { CAboutDlg dlgAbout; dlgAbout.DoModal(); } else { CDialog::OnSysCommand(nID, lParam); } } /////////////////在屏幕上显示图像/////////////////// void CADOBlobDlg::DrawUserPhoto(int x, int y, CDC *pDC) { if(!m_hPhotoBitmap) return; HBITMAP OldBitmap; CDC MemDC; MemDC.CreateCompatibleDC(pDC); OldBitmap=(HBITMAP)MemDC.SelectObject(m_hPhotoBitmap); pDC->BitBlt(x,y,100,130,&MemDC,0,0,SRCCOPY); MemDC.SelectObject(OldBitmap); } void CADOBlobDlg::OnPaint() { CPaintDC dc(this); if (IsIconic()) { 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 { DrawUserPhoto(50,30,&dc); CDialog::OnPaint(); } } HCURSOR CADOBlobDlg::OnQueryDragIcon() { return (HCURSOR) m_hIcon; } void CADOBlobDlg::OnAddUser() { if(m_bModify) { int nRet = MessageBox("当前用户信息尚未保存，是否保存?","VC知识库 WWW.VCKBASE.COM",MB_YESNOCANCEL); switch(nRet) { case IDCANCEL: return; case IDYES: OnSaveinfo(); break; case IDNO: default: break; } } m_editUserName.EnableWindow(); m_editOld.EnableWindow(); m_buttonSelectPhoto.EnableWindow(); m_buttonDeleteUser.EnableWindow(FALSE); m_Old = ""; m_UserName = ""; m_bModify = FALSE; m_bNewUser = TRUE; UpdateData(FALSE); DestroyPhoto(); Invalidate(); } //////////////删除用户////////////// void CADOBlobDlg::OnDeleteUser() { m_pRecordset->Delete(adAffectCurrent); if(m_pRecordset->adoEOF) m_pRecordset->MoveLast(); ResetControls(); m_buttonDeleteUser.EnableWindow(FALSE); ReadData(); Invalidate(); } void CADOBlobDlg::OnChangeUsername() { m_bModify = TRUE; m_buttonSaveInfo.EnableWindow(); } void CADOBlobDlg::OnChangeOld() { m_bModify = TRUE; m_buttonSaveInfo.EnableWindow(); } ////////////////保存用户信息///////////////// void CADOBlobDlg::OnSaveinfo() { if(!m_bModify) return; UpdateData(); if(m_pBMPBuffer == NULL || m_hPhotoBitmap == NULL || m_UserName == "" || m_Old == "") { AfxMessageBox("您没有提供完整的用户信息。\r\n这些信息包括:用户名、年龄、照片"); return; } m_buttonSaveInfo.EnableWindow(FALSE); char *pBuf = m_pBMPBuffer; VARIANT varBLOB; SAFEARRAY *psa; SAFEARRAYBOUND rgsabound[1]; if(m_bNewUser) m_pRecordset->AddNew(); m_pRecordset->PutCollect("username",_variant_t(m_UserName)); m_pRecordset->PutCollect("old",atol(m_Old)); if(pBuf) { rgsabound[0].lLbound = 0; rgsabound[0].cElements = m_nFileLen; psa = SafeArrayCreate(VT_UI1, 1, rgsabound