picturedlg.cpp

VC中实现对SQL存储图片的操作,并在MFC中进行显示

// pictureDlg.cpp : implementation file
//

#include "stdafx.h"
#include "picture.h"
#include "pictureDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
static CString m_connect="";

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()

/////////////////////////////////////////////////////////////////////////////
// CPictureDlg dialog

CPictureDlg::CPictureDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CPictureDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CPictureDlg)
	m_Sql = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
	m_hPictureBitmap=NULL;
	m_pBMPBuffer = NULL;
	pado=NULL;
	strPicturePath="";
	bFlag = FALSE;
	bStretchToFit=TRUE;
}

void CPictureDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CPictureDlg)
	DDX_Text(pDX, IDC_EDIT_SQL, m_Sql);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CPictureDlg, CDialog)
	//{{AFX_MSG_MAP(CPictureDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(ID_UploadPicture, OnUploadPicture)
	ON_BN_CLICKED(ID_ChoosePicture, OnChoosePicture)
	ON_BN_CLICKED(ID_DownloadPrePicture, OnDownloadPrePicture)
	ON_BN_CLICKED(ID_DownloadNextPicture, OnDownloadNextPicture)
	ON_BN_CLICKED(ID_ShowPicture, OnShowPicture)
	ON_BN_CLICKED(IDC_RADIO_Stretch, OnRADIOStretch)
	ON_BN_CLICKED(IDC_RADIO_Copy, OnRADIOCopy)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CPictureDlg message handlers

BOOL CPictureDlg::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
	
	// TODO: Add extra initialization here
	SetWindowText("~~Visual C++--SQL--Picture~~");
	CheckRadioButton(IDC_RADIO_Stretch, IDC_RADIO_Copy, IDC_RADIO_Stretch);

	if(m_connect.GetLength()<=0)
	{
		m_connect="Provider=SQLOLEDB.1;Password=386153;Persist Security Info=True;User ID=sa;Initial Catalog=student;Data Source=(local)";
	}

	::CoInitialize(NULL);
	Open();

	if(m_pSet.CreateInstance("ADODB.Recordset")!=S_OK) 
		return false;
	HRESULT hr = m_pSet->Open("SELECT * FROM picture ",pado.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
	if(SUCCEEDED(hr))
	{
		ReadData();
	}

    ResetControls();

	return TRUE;  // return TRUE  unless you set the focus to a control
}

void CPictureDlg::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 CPictureDlg::OnPaint() 
{
	CPaintDC dc(this); // device context for painting
	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
	{
		if(bFlag)
		    DrawPicture(30,30,&dc);
		CDialog::OnPaint();
	}
}

// The system calls this to obtain the cursor to display while the user drags
//  the minimized window.
HCURSOR CPictureDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CPictureDlg::OnUploadPicture() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
 
	CFile fp;
	if(!fp.Open(strPicturePath,CFile::modeRead)) 
	{
		m_pSet->Close();
		m_pSet->Release();
		return;
	}
	DWORD len=fp.GetLength();
	BYTE* bt=new BYTE[len];
	if(bt==NULL)
	{
		fp.Close();
		m_pSet->Close();
		m_pSet->Release();
		return;
	}
	fp.ReadHuge(bt,len);//可从文件的当前位置读取大于64K数据
	fp.Close();

	m_pSet->AddNew();
	m_pSet->PutCollect("serial",_variant_t(m_Sql));
	
	//SAFEARRAY 结构类型
	VARIANT			varBLOB;
	SAFEARRAY		*psa;
	SAFEARRAYBOUND	rgsabound[1];
	rgsabound[0].lLbound = 0;
	rgsabound[0].cElements = len;
	psa = SafeArrayCreate(VT_UI1, 1, rgsabound);
	for (long k = 0; k < (long)len; k++)
		SafeArrayPutElement (psa, &k, bt++);  
	varBLOB.vt = VT_ARRAY | VT_UI1;
	varBLOB.parray = psa;
	//BLOB数据的读取：
	//对应于保存数据时我们所使用的AppendChunk函数，读取数据应该使用GetChunk函数
	m_pSet->GetFields()->GetItem("pic")->AppendChunk(varBLOB);	
	m_pSet->Update(); 
	
	SafeArrayDestroy(psa);

	UpdateData(false);
	AfxMessageBox("上传图片至SQL成功");
	return;
}

void CPictureDlg::Open()
{
	try
	{
		pado.CreateInstance(__uuidof(Connection));
		pado->Open((const char *)m_connect,"","",-1);
	}
	catch(...)
	{
		AfxMessageBox("打开数据库失败");
		return;
	}
	return;
}
void CPictureDlg::OnChoosePicture() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
	static char BASED_CODE szFilter[]="bmp style(*.bmp)|*.bmp||";
	CFileDialog fd(true,NULL,NULL,OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT,szFilter,NULL);
	if(fd.DoModal()==IDOK)
		strPicturePath=fd.GetPathName();
	else
	{
		MessageBox("请选择图片的正确地址","选择失败",MB_OK);
		return;
	}
	UpdateData(false);
	return;
}

//在屏幕上显示图像
void CPictureDlg::DrawPicture(int x, int y, CDC *pDC)
{
	if(!m_hPictureBitmap) return;
	HBITMAP OldBitmap;
	CDC MemDC;
	MemDC.CreateCompatibleDC(pDC);
	OldBitmap=(HBITMAP)MemDC.SelectObject(m_hPictureBitmap);
	
	//拉伸显示
	if(bStretchToFit)
	{
	    //取得BMP图像的Width与Height
	    CBitmap bmpImage;
        bmpImage.Attach (m_hPictureBitmap);
	    BITMAP bmpInfo;
	    bmpImage.GetBitmap(&bmpInfo);
        CSize pSize = CSize(bmpInfo.bmWidth, bmpInfo.bmHeight );
	    pDC->StretchBlt(x,y,100,130,&MemDC,0,0,pSize.cx,pSize.cy,SRCCOPY);
	    MemDC.SelectObject(OldBitmap);
	}
	else
	{
        pDC->BitBlt(x,y,100,130,&MemDC,0,0,SRCCOPY);
	}
}

//清除分配的对象
void CPictureDlg::DestroyPicture()
{
	if(m_hPictureBitmap)
	{
		DeleteObject(m_hPictureBitmap);
		m_hPictureBitmap = NULL;
	}
	if(m_pBMPBuffer)
	{
		delete m_pBMPBuffer;
		m_pBMPBuffer = NULL;
	}
}

void CPictureDlg::OnDownloadPrePicture() 
{
	// TODO: Add your control notification handler code here
	m_pSet->MovePrevious();
	if(m_pSet->BOF)
		m_pSet->MoveFirst();
	ReadData();
	ResetControls();
	Invalidate(true);
}

void CPictureDlg::OnDownloadNextPicture() 
{
	// TODO: Add your control notification handler code here
	m_pSet->MoveNext();
	if(m_pSet->adoEOF)
		m_pSet->MoveLast();
	ReadData();
	ResetControls();
	Invalidate(true);
}

//读取记录集当前记录中数据，包括图像数据
void CPictureDlg::ReadData()
{
	UpdateData(true);
	DestroyPicture();//清除原图像
	if(m_pSet->adoEOF||m_pSet->BOF) 
	{
	    AfxMessageBox("无图片");
		return;
	}
	long lDataSize = m_pSet->GetFields()->GetItem("pic")->ActualSize;
	if(lDataSize > 0)
	{
		_variant_t	varBLOB;
		varBLOB = m_pSet->GetFields()->GetItem("pic")->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_hPictureBitmap = BufferToHBITMAP();					///生成BITMAP对象
			}
		}
	}

	m_Sql = m_pSet->GetCollect("serial").bstrVal;
	UpdateData(false);
}

//将内存中的BMP文件内容转换到HBITMAP
HBITMAP CPictureDlg::BufferToHBITMAP()
{
	HBITMAP				hBmp;
	LPSTR				hDIB,lpBuffer = m_pBMPBuffer;
	LPVOID				lpDIBBits;
	BITMAPFILEHEADER	bmfHeader;
	DWORD				bmfHeaderLen;

	bmfHeaderLen = sizeof(bmfHeader);
	strncpy((LPSTR)&bmfHeader,(LPSTR)lpBuffer,bmfHeaderLen);

	if (bmfHeader.bfType != (*(WORD*)"BM")) return NULL;
	hDIB = lpBuffer + bmfHeaderLen;
	BITMAPINFOHEADER &bmiHeader = *(LPBITMAPINFOHEADER)hDIB ;
	BITMAPINFO &bmInfo = *(LPBITMAPINFO)hDIB ;

	lpDIBBits=(lpBuffer)+((BITMAPFILEHEADER *)lpBuffer)->bfOffBits;
	CClientDC dc(this);
	hBmp = CreateDIBitmap(dc.m_hDC,&bmiHeader,CBM_INIT,lpDIBBits,&bmInfo,DIB_RGB_COLORS);
	return hBmp;
}

BOOL CPictureDlg::DestroyWindow() 
{
	// TODO: Add your specialized code here and/or call the base class
	m_pSet->Close();
    bFlag = FALSE;
	return CDialog::DestroyWindow();
}

void CPictureDlg::OnShowPicture() 
{
	// TODO: Add your control notification handler code here
	UpdateData(true);
	bFlag=true;
	Invalidate(true);
	GetDlgItem(ID_ShowPicture)->EnableWindow(false);
    GetDlgItem(IDC_RADIO_Stretch)->EnableWindow(false);
    GetDlgItem(IDC_RADIO_Copy)->EnableWindow(false);
	UpdateData(false);
}

void CPictureDlg::ResetControls()
{
	BOOL IsFirstRecord = FirstRecord();
	BOOL IsLastRecord = LastRecord();
	GetDlgItem(ID_DownloadPrePicture)->EnableWindow(!IsFirstRecord);
	GetDlgItem(ID_DownloadNextPicture)->EnableWindow(!IsLastRecord);
}

//判断是否是最后一个记录
BOOL CPictureDlg::LastRecord()
{
	if(m_pSet->adoEOF)
	{
		return TRUE;
	}
	m_pSet->MoveNext();
	if(m_pSet->adoEOF)
	{
		m_pSet->MovePrevious();
		return TRUE;
	}
	else
	{
		m_pSet->MovePrevious();
		return FALSE;
	}

}

//判断是否是第一个记录
BOOL CPictureDlg::FirstRecord()
{
	if(m_pSet->BOF)
	{
		return TRUE;
	}
	m_pSet->MovePrevious();
	if(m_pSet->BOF)
	{
		m_pSet->MoveFirst();
		return TRUE;
	}
	else
	{
		m_pSet->MoveNext();
		return FALSE;
	}
}

void CPictureDlg::OnRADIOStretch() 
{
	// TODO: Add your control notification handler code here
    bStretchToFit=TRUE;
	Invalidate(true);
}

void CPictureDlg::OnRADIOCopy() 
{
	// TODO: Add your control notification handler code here
	bStretchToFit=FALSE;
    Invalidate(true);
}