filesysdlg.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

// FileSysDlg.cpp : implementation file
//

#include "stdafx.h"
#include "FileSys.h"
#include "FileSysDlg.h"

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif
#define ChunkSize    200
/////////////////////////////////////////////////////////////////////////////
// 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()

/////////////////////////////////////////////////////////////////////////////
// CFileSysDlg dialog

CFileSysDlg::CFileSysDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CFileSysDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CFileSysDlg)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
	// Note that LoadIcon does not require a subsequent DestroyIcon in Win32
	m_hIcon = AfxGetApp()->LoadIcon(IDR_MAINFRAME);

}

void CFileSysDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CFileSysDlg)
	DDX_Control(pDX, IDC_LIST_FILENAME, m_ListFileName);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CFileSysDlg, CDialog)
	//{{AFX_MSG_MAP(CFileSysDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_BUTTON_SAVE, OnButtonSave)
	ON_BN_CLICKED(IDC_BUTTON_GET, OnButtonGet)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CFileSysDlg message handlers

BOOL CFileSysDlg::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
	m_pCon.CreateInstance(__uuidof(Connection));
	m_pRS.CreateInstance(__uuidof(Recordset));
	//初始化数据库连接
	//m_pCon->ConnectionString="File Name=my_data4.udl";
	m_pCon->ConnectionString="Provider=SQLOLEDB.1;Integrated Security=SSPI;Persist Security Info=False;Initial Catalog=FileDB;Data Source=(local)";
	m_pCon->Open("","","",adModeUnknown);
	//初始化List控件
	m_ListFileName.InsertColumn(0,"ID",LVCFMT_LEFT,40,-1);
	m_ListFileName.InsertColumn(1,"文件名",LVCFMT_LEFT,200,-1);	
	m_ListFileName.SetExtendedStyle(LVS_EX_FULLROWSELECT| LVS_EX_GRIDLINES);
	RefreshList();
	return TRUE;  // return TRUE  unless you set the focus to a control
}

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

void CFileSysDlg::OnButtonSave() 
{
	CFile file;
	//BOOL bret;
try{
	m_pRS->Open(_variant_t("tbFile"), 
				m_pCon.GetInterfacePtr(),	
				adOpenDynamic,
				adLockOptimistic,
				adCmdTable);
	if(m_pRS->Fields->GetItem(long(2))->GetAttributes() & adFldLong)
	{	
		CFileDialog fileDlg(TRUE,NULL,NULL,OFN_HIDEREADONLY|OFN_OVERWRITEPROMPT,"All Files(*.*)|*.*||",NULL);
		if(fileDlg.DoModal()==IDOK)
		{
			if(file.Open(fileDlg.GetPathName(),CFile::modeRead))
			{
				long length = (long)file.GetLength();
				BYTE *pbuf = new BYTE[length];
				if (pbuf != NULL && file.Read(pbuf, length) == (DWORD)length)
				{			
					m_pRS->AddNew();
					m_pRS->Fields->GetItem(long(1))->PutValue(_variant_t(fileDlg.GetFileName()));
					MyAppendChunk(FieldPtr(m_pRS->GetFields()->GetItem(long(2))), pbuf, length);
					m_pRS->Update();
				}
				if (pbuf != NULL) 
					delete[] pbuf;
				file.Close();
			}		
		}
	}
	m_pRS->Close();
	}
	catch (_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
		return;
	}  
	RefreshList();
}


BOOL CFileSysDlg::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;
	}
}

void CFileSysDlg::RefreshList()
{
	_variant_t var;
	CString strValue;
	int curItem=0;
	try
	{
		m_pRS->Open(_variant_t("tbFile"), 
			m_pCon.GetInterfacePtr(),	
			adOpenDynamic,
			adLockOptimistic,
			adCmdTable);
		if(m_pRS->GetRecordCount()==0)
		{m_pRS->Close();
			return;
		}
		else{
			m_ListFileName.DeleteAllItems();
		}
		while(!m_pRS->adoEOF)
		{
			var=m_pRS->Fields->GetItem(long(0))->GetValue();
			if(var.vt != VT_NULL)
				strValue = (LPCSTR)_bstr_t(var);
			m_ListFileName.InsertItem(curItem,strValue);

			var=m_pRS->Fields->GetItem(long(1))->GetValue();
			if(var.vt != VT_NULL)
				strValue = (LPCSTR)_bstr_t(var);
			m_ListFileName.SetItemText(curItem,1,strValue);
			
			m_pRS->MoveNext();
			curItem++;
		}
		m_pRS->Close();
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
		m_pRS->Close();
		return;
	}  
}

BOOL CFileSysDlg::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;
}

void CFileSysDlg::OnButtonGet() 
{
	CString strid,strSQL,fileName;
	CFile file;
	long size;
	int sel=m_ListFileName.GetSelectionMark();
	if(sel<0)
	{
		MessageBox("请选择要提取的文件.");
		return;
	}
	strid=m_ListFileName.GetItemText(sel,0);
	fileName=m_ListFileName.GetItemText(sel,1);
	strSQL="select * from tbFile where ID="+strid;

	m_pRS->Open(_variant_t(strSQL),
		m_pCon.GetInterfacePtr(),	
		adOpenDynamic,
		adLockOptimistic,
		adCmdText);

	if(!m_pRS->adoEOF)
	{

		size=m_pRS->Fields->GetItem(long(2))->ActualSize;
		if(size>0 && (m_pRS->Fields->GetItem(long(2))->GetAttributes() & adFldLong))
		{
			BYTE *lpData = new BYTE[size];
			if(MyGetChunk(m_pRS->GetFields()->GetItem(long(2)),(LPVOID)lpData))
			{
				file.Open(fileName,CFile::modeCreate|CFile::modeReadWrite);
				file.Write(lpData,size);
				MessageBox("提取完成，文件保存在程序运行的目录下");
			}	
		}		
	}
	m_pRS->Close();
		
}