rwdatadlg.cpp

用VC编写的读取SQL数据库的小程序

/********************************************************************/

/* 文件名: RWDataDlg.cpp                                            */

/*                                                                  */

/* 作者: 李  兴                  时间: 2004.11.15                    */


/********************************************************************/

 

#include "stdafx.h"
#include "RWData.h"
#include "RWDataDlg.h"
#include "CurYCData.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()

/////////////////////////////////////////////////////////////////////////////
// CRWDataDlg dialog

CRWDataDlg::CRWDataDlg(CWnd* pParent /*=NULL*/)
	: CDialog(CRWDataDlg::IDD, pParent)
{
	//{{AFX_DATA_INIT(CRWDataDlg)
		// 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 CRWDataDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CRWDataDlg)
	DDX_Control(pDX, IDC_LIST1, m_ListCon);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CRWDataDlg, CDialog)
	//{{AFX_MSG_MAP(CRWDataDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_WM_TIMER()
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CRWDataDlg message handlers

BOOL CRWDataDlg::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
	First = TRUE;
	count = 1;
	SetTimer(1,2000,NULL);
	SetTimer(2,1000,NULL);

	m_ListCon.InsertColumn(0,"点序号",10,50);
	m_ListCon.InsertColumn(1,"遥测值",10,100);
	
	return TRUE;  // return TRUE  unless you set the focus to a control
}

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



void CRWDataDlg::OnTimer(UINT nIDEvent) 
{

	switch(nIDEvent)
	{
		case(1):
			if(First)
			{	
				First = FALSE;
				WriteDataBase();
			}
			else
				UpdateDataBase();
		case 2:
			ReadDataBase();
		default:
			break;
	}
	CDialog::OnTimer(nIDEvent);
}

void CRWDataDlg::WriteDataBase()
{
	if(!m_database.IsOpen())
	{
		if(!m_database.Open(_T("Data")))
			ASSERT("不能打开到该数据源的连接！");
	}
	CString strSQL;
	CCurYCData m_recordset(&m_database);
	strSQL.Format("select * from CurYCData ");
	m_recordset.Open(AFX_DB_USE_DEFAULT_TYPE,strSQL);
	if(m_recordset.GetRecordCount()==0)
	{
		for (int i=1; i < 20; i++ ) 
		{
			strSQL.Format("insert into CurYCData VALUES(%d,%d)",i,i);
			m_database.ExecuteSQL(strSQL);
		}
	}
	else
	{
		strSQL.Format("delete CurYCData ");
		m_database.ExecuteSQL(strSQL);
		First = TRUE;
	}
	m_database.Close();	

}




void CRWDataDlg::UpdateDataBase()
{
	if(!m_database.IsOpen())
	{
		if(!m_database.Open(_T("Data")))
			ASSERT("不能打开到该数据源的连接！");
	}
	CString strSQL;
	for (int i=1; i < 20; i++ ) 
	{
		strSQL.Format("Update CurYCData SET Value = %f WHERE (Id = %d)",(count+0.01),i);
		m_database.ExecuteSQL(strSQL);
		count++;
	}
	m_database.Close();	
	if(count > 10000)
		count = 0;
}

void CRWDataDlg::ReadDataBase()
{

	if(!m_database.IsOpen()){
		m_database.Open(_T("Data"));
	}
	m_ListCon.DeleteAllItems();
	CCurYCData m_recordset(&m_database);
	CString strSQL;
	strSQL.Format("select * from CurYCData");
	m_recordset.Open(AFX_DB_USE_DEFAULT_TYPE,strSQL);
	CDBVariant varValue;
	if(m_recordset.GetRecordCount()!=0) m_recordset.MoveFirst();
	char buf[20];
	int i=0;
	while(!m_recordset.IsEOF())
	{
		int temp=0;
		m_recordset.GetFieldValue(temp,varValue);
		sprintf(buf,"%d",varValue.m_iVal); 
		m_ListCon.InsertItem(i,buf);
		m_recordset.GetFieldValue(1,varValue);
		m_ListCon.SetItemText(i,1,varValue.m_pstring->GetBuffer(1));
		m_recordset.MoveNext();
		i++;
	}
}