accessdlg.cpp

数据存储的程序例子

// accessDlg.cpp : implementation file
//

#include "stdafx.h"
#include "access.h"
#include "accessDlg.h"

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

/////////////////////////////////////////////////////////////////////////////
// CAboutDlg dialog used for App About
extern CAccessApp theApp; 
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()

/////////////////////////////////////////////////////////////////////////////
// CAccessDlg dialog

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

void CAccessDlg::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CAccessDlg)
	DDX_Control(pDX, IDC_LIST_DATA, m_listCtl);
	DDX_Text(pDX, IDC_EDIT_AGE, m_Age);
	DDX_Text(pDX, IDC_EDIT_NAME, m_Name);
	//}}AFX_DATA_MAP
}

BEGIN_MESSAGE_MAP(CAccessDlg, CDialog)
	//{{AFX_MSG_MAP(CAccessDlg)
	ON_WM_SYSCOMMAND()
	ON_WM_PAINT()
	ON_WM_QUERYDRAGICON()
	ON_BN_CLICKED(IDC_READ, OnRead)
	ON_BN_CLICKED(IDC_ADD, OnAdd)
	ON_BN_CLICKED(IDC_MODIFY, OnModify)
	ON_BN_CLICKED(IDC_DELETE, OnDelete)
	ON_WM_DESTROY()
	ON_LBN_SELCHANGE(IDC_LIST_DATA, OnSelchangeListData)
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CAccessDlg message handlers

BOOL CAccessDlg::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
	// 使用ADO创建数据库记录集
	m_pRecordset.CreateInstance(__uuidof(Recordset));

	// 在ADO操作中建议语句中要常用try...catch()来捕获错误信息，
	// 因为它有时会经常出现一些想不到的错误。jingzhou xu
	try
	{
		m_pRecordset->Open("SELECT * FROM DemoTable",                // 查询DemoTable表中所有字段
							theApp.m_pConnection.GetInterfacePtr(),	 // 获取库接库的IDispatch指针
							adOpenDynamic,
							adLockOptimistic,
							adCmdText);
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
	}

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

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

void CAccessDlg::OnRead() 
{
	// TODO: Add your control notification handler code here
	_variant_t var;
	CString strName,strAge;

	// 清空列表框
	m_listCtl.ResetContent();
	strName=strAge="";

	// 在ADO操作中建议语句中要常用try...catch()来捕获错误信息，
	// 因为它有时会经常出现一些想不到的错误。jingzhou xu
	try
	{
		if(!m_pRecordset->BOF)
			m_pRecordset->MoveFirst();
		else
		{
			AfxMessageBox("表内数据为空");
			return;
		}

		// 读入库中各字段并加入列表框中
		while(!m_pRecordset->adoEOF)
		{
			var = m_pRecordset->GetCollect("Name");
			if(var.vt != VT_NULL)
				strName = (LPCSTR)_bstr_t(var);
			var = m_pRecordset->GetCollect("Age");
			if(var.vt != VT_NULL)
				strAge = (LPCSTR)_bstr_t(var);

			m_listCtl.AddString( strName + " --> "+strAge );

			m_pRecordset->MoveNext();
		}

		// 默认列表指向第一项，同时移动记录指针并显示
		m_listCtl.SetCurSel(0);
		OnSelchangeListData();
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
	}
}

void CAccessDlg::OnAdd() 
{
	// TODO: Add your control notification handler code here
		UpdateData();
	if(m_Name == "" || m_Age == "")
	{
		AfxMessageBox("姓名和年龄信息不能为空!");
		return;
	}

	// 在ADO操作中建议语句中要常用try...catch()来捕获错误信息，
	// 因为它有时会经常出现一些想不到的错误。
	try
	{
		// 写入各字段值
		m_pRecordset->AddNew();
		m_pRecordset->PutCollect("Name", _variant_t(m_Name));
		m_pRecordset->PutCollect("Age", atol(m_Age));
		m_pRecordset->Update();

		AfxMessageBox("插入成功!");

		// 更新显示其库内容
		int nCurSel = m_listCtl.GetCurSel();
		OnRead();
		m_listCtl.SetCurSel(nCurSel);
		// 移动记录指针到新的位置
		OnSelchangeListData();
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
	}

}

void CAccessDlg::OnModify() 
{
	// TODO: Add your control notification handler code here
	UpdateData();        // 更新对话框数据
	if(m_listCtl.GetCount() == 0 || m_Name == "" || m_Age == "")
	{
		AfxMessageBox("表中记录数为空或姓名和年龄信息没有设置!");
		return;
	}
	else if(m_listCtl.GetCurSel() < 0 || m_listCtl.GetCurSel() > m_listCtl.GetCount())
		m_listCtl.SetCurSel(0);

	// 修改当前记录的字段值
	try
	{
		m_pRecordset->PutCollect("Name", _variant_t(m_Name));
		m_pRecordset->PutCollect("Age", atol(m_Age));
		m_pRecordset->Update();

		// 重新读入库记录更新显示
		int nCurSel = m_listCtl.GetCurSel();
		OnRead();
		m_listCtl.SetCurSel(nCurSel);
		// 移动记录指针到新的位置
		OnSelchangeListData();
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
	}

}

void CAccessDlg::OnDelete() 
{
	// TODO: Add your control notification handler code here
		if(m_listCtl.GetCount() == 0)
		return;
	else if(m_listCtl.GetCurSel() < 0 || m_listCtl.GetCurSel() > m_listCtl.GetCount())
		m_listCtl.SetCurSel(0);

	try
	{
		// 删除当前行记录
		m_pRecordset->Delete(adAffectCurrent);
		m_pRecordset->Update();

		// 删除列表中当前值
		int nCurSel = m_listCtl.GetCurSel();
		m_listCtl.DeleteString(nCurSel);
		if(nCurSel == 0 && (m_listCtl.GetCount() != 0))
			m_listCtl.SetCurSel(nCurSel);
		else if(m_listCtl.GetCount() != 0)
			m_listCtl.SetCurSel(nCurSel-1);
		
		// 移动记录指针到新的位置
		OnSelchangeListData();
	}
	catch(_com_error *e)
	{
		AfxMessageBox(e->ErrorMessage());
	}

}



void CAccessDlg::OnDestroy() 
{
	CDialog::OnDestroy();
	
	// TODO: Add your message handler code here
	m_pRecordset->Close();
	m_pRecordset = NULL;
}

void CAccessDlg::OnSelchangeListData() 
{
	// TODO: Add your control notification handler code here
	int curSel = m_listCtl.GetCurSel();		
 	_variant_t var,varIndex;
 
 	if(curSel < 0)
 		return;
 
 	try
 	{
 		// 先将指针移向第一条记录，然后就可以相对第一条记录来随意移动记录指针
 		m_pRecordset->MoveFirst();
 		m_pRecordset->Move(long(curSel));
 		
 		var = m_pRecordset->GetCollect("Name");
 		if(var.vt != VT_NULL)
 			m_Name = (LPCSTR)_bstr_t(var);
 		var = m_pRecordset->GetCollect("Age");
 		if(var.vt != VT_NULL)
 			m_Age = (LPCSTR)_bstr_t(var);
 		
 		UpdateData(false);
 	}
 	catch(_com_error *e)
 	{
 		AfxMessageBox(e->ErrorMessage());
 	}
}