bmpsysdlg.cpp

Visual C++实践与提高－－数据库开发与工程应用篇 随书代码 希望对用ADO开发的人会有所帮助 这是第8、9章的

// BMPSysDlg.cpp : implementation file
//

#include "stdafx.h"
#include "BMPSys.h"
#include "BMPSysDlg.h"
#include "picture.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()

/////////////////////////////////////////////////////////////////////////////
// CBMPSysDlg dialog

CBMPSysDlg::CBMPSysDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CBMPSysDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CBMPSysDlg)
	m_strName = _T("");
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);
}

void CBMPSysDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CBMPSysDlg)
	DDX_Control(pDX, IDC_BUTTON_PRE, m_btnPre);
	DDX_Control(pDX, IDC_BUTTON_NEXT, m_btnNext);
	DDX_Text(pDX, IDC_STATIC_NAME, m_strName);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CBMPSysDlg, CDialog)
	//{{AFX_MSG_MAP(CBMPSysDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_PRE, OnButtonPre)
	ON_BN_CLICKED(IDC_BUTTON_NEXT, OnButtonNext)
	ON_BN_CLICKED(IDC_BUTTON_FIRST, OnButtonFirst)
	ON_BN_CLICKED(IDC_BUTTON_LAST, OnButtonLast)
	ON_BN_CLICKED(IDC_BUTTON_NEW, OnButtonNew)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CBMPSysDlg message handlers

BOOL CBMPSysDlg::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
		
	try
		{  
		m_pConnection.CreateInstance(__uuidof(Connection));
		m_pConnection->ConnectionString="File Name=my_data9.udl";
	 	m_pConnection->Open("","","",adModeUnknown);
		m_pRecordset.CreateInstance(__uuidof(Recordset));
		m_pRecordset->Open(_variant_t("tbBmp"), 
					m_pConnection.GetInterfacePtr(),	
					adOpenDynamic,
					adLockOptimistic,
					adCmdTable);	
		}
	    catch (_com_error e) 
		{
			AfxMessageBox("数据库连接失败!");
			return FALSE;
	    }

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

void CBMPSysDlg::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 CBMPSysDlg::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 CBMPSysDlg::OnQueryDragIcon()
{
	return (HCURSOR) m_hIcon;
}

void CBMPSysDlg::OnButtonPre() 
{
	m_pRecordset->MovePrevious();

	if(m_pRecordset->BOF)
	{   
		m_btnPre.EnableWindow(FALSE);
		m_pRecordset->MoveNext();
		ShowPic();
		return;
	}
	else {
			ShowPic();
	}
	m_btnNext.EnableWindow(TRUE);
}

void CBMPSysDlg::OnButtonNext() 
{
	m_pRecordset->MoveNext();

	if(m_pRecordset->adoEOF)
	{
		m_pRecordset->MovePrevious();
		m_btnNext.EnableWindow(FALSE);
		ShowPic();
	}
    else {
			ShowPic();
    }
	m_btnPre.EnableWindow(TRUE);
	
}
void CBMPSysDlg::OnButtonFirst() 
{
	if(m_pRecordset!=NULL)
	{
		m_pRecordset->MoveFirst();
		ShowPic();
	}
    m_btnPre.EnableWindow(FALSE);
}
void CBMPSysDlg::OnButtonLast() 
{
	if(m_pRecordset!=NULL)
	{
		m_pRecordset->MoveLast();
		ShowPic();
	}	
	m_btnNext.EnableWindow(FALSE);
}
/*
void CBMPSysDlg::OnButtonReset() 
{
	static char BASED_CODE szFilter[] = "BMP Files (*.bmp)|*.bmp|All Files (*.*)|*.*||";
	CFileDialog dlg(TRUE,"BMP",NULL,  OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,szFilter);
	if (dlg.DoModal() == IDOK)
	{
		CString m_strPathName = dlg.GetPathName();
		if (m_strPathName != "")
		{   MessageBox(m_strPathName);
			AppendChunkF(m_strPathName);
		}
	}
}*/
void CBMPSysDlg::OnButtonNew() 
{
	static char BASED_CODE szFilter[] = "BMP Files (*.bmp)|*.bmp|All Files (*.*)|*.*||";
	CFileDialog dlg(TRUE,"BMP",NULL,  OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,szFilter);
	if (dlg.DoModal() == IDOK)
	{
		CString m_strPathName = dlg.GetPathName();
		if (m_strPathName != "")
		{   
			CFile file;
			if (file.Open(m_strPathName, CFile::modeRead))
			{
				long length = (long)file.GetLength();
				BYTE *pbuf = new BYTE[length];
				if (pbuf != NULL && file.Read(pbuf, length) == (DWORD)length)
				{	m_pRecordset->AddNew();
					m_pRecordset->Fields->GetItem(long(1))->PutValue(_variant_t(dlg.GetFileName()));
					MyAppendChunk(FieldPtr(m_pRecordset->GetFields()->GetItem(_bstr_t("Bmp"))), pbuf, length);
					m_pRecordset->Update();
				}		
				if (pbuf != NULL) delete[] pbuf;	
				file.Close();
			}
		}
	}	
}

void CBMPSysDlg::ShowPic()
{
	if(m_pRecordset==NULL)
		return;	
	_variant_t var;
	CString strValue;
	var=m_pRecordset->Fields->GetItem(_bstr_t("Name"))->GetValue();
	if(var.vt != VT_NULL)
		strValue = (LPCSTR)_bstr_t(var);
	m_strName=strValue;
	UpdateData(FALSE);
	//获得图片数据，显示图片
	long size = m_pRecordset->Fields->GetItem(_bstr_t("Bmp"))->ActualSize;
	if ( size > 0)
	{  
		BYTE *lpData = new BYTE[size];
		if (MyGetChunk(m_pRecordset->GetFields()->GetItem("Bmp"), (LPVOID)lpData))
		{  
			CPicture m_Pic;
			m_Pic.LoadPictureData(lpData,size);
			CClientDC dc(this);        
			m_Pic.UpdateSizeOnDC(&dc); 
			m_Pic.Show(&dc, CRect(170,100,170+200,100+200) );
		}
		delete[] lpData;
		lpData = NULL;
	}
	else if(size==0)  MessageBox("该记录为空!");
}


BOOL CBMPSysDlg::MyAppendChunk(FieldPtr pField, LPVOID lpData, UINT nBytes)
{
	SAFEARRAY FAR *pSafeArray = NULL;
	SAFEARRAYBOUND rgsabound[1];
	
	try
	{
		rgsabound[0].lLbound = 0;
		rgsabound[0].cElements = nBytes;
		pSafeArray = SafeArrayCreate(VT_UI1, 1, rgsabound);
		
		for (long i = 0; i < (long)nBytes; i++)
		{
			UCHAR &chData	= ((UCHAR*)lpData)[i];
			HRESULT hr = SafeArrayPutElement(pSafeArray, &i, &chData);
			if (FAILED(hr))	return FALSE;
		}
		
		_variant_t varChunk;
		varChunk.vt = VT_ARRAY | VT_UI1;
		varChunk.parray = pSafeArray;
		
		return (pField->AppendChunk(varChunk) == S_OK);
	}
	catch (_com_error &e)
	{
		TRACE(_T("Warning: AppendChunk 方法发生异常. 错误信息: %s; 文件: %s; 行: %d\n"), e.ErrorMessage(), __FILE__, __LINE__);
		return FALSE;
	}
}


BOOL CBMPSysDlg::MyGetChunk(FieldPtr pField, LPVOID lpData)
{
	ASSERT(pField != NULL);
	ASSERT(lpData != NULL);
	
	UCHAR chData;
	long index = 0;
	
	while (index < pField->ActualSize)
	{ 
		try
		{
			_variant_t varChunk = pField->GetChunk(pField->ActualSize);
			if (varChunk.vt != (VT_ARRAY | VT_UI1))
			{
				return FALSE;
			}
			
            for (long i = 0; i < pField->ActualSize; i++)
            {
                if (SUCCEEDED( SafeArrayGetElement(varChunk.parray, &i, &chData) ))
                {
					((UCHAR*)lpData)[index] = chData;
                    index++;
                }
                else
				{
                    break;
				}
            }
		}
		catch (_com_error e)
		{
			TRACE(_T("Warning: GetChunk 方法发生异常. 错误信息: %s; 文件: %s; 行: %d\n"), e.ErrorMessage(), __FILE__, __LINE__);
			return FALSE;
		}
	}
	
	return TRUE;
}