[MFC学习]1.ADO编程——读取数据

1.新建一个对话框MFC项目，命名为MineGeology。

2.导入msado15.dll类库，在stdafx.h文件中输入：

#import "C:\Program Files\Common Files\System\ado\msado15.dll" no_namespace\
    rename("EOF","adoEOF") rename("BOF","adoBOF")

用.udl文件设置连接字符串

3.封装操作ADO的类CADOHelper。

 1 #pragma once
 2 class CADOHelper
 3 {
 4 
 5 public:    
 6     _ConnectionPtr m_pConnection;//_com_ptr_t智能指针
 7     _RecordsetPtr m_pRecordset; 
 8     CString connStr;
 9 public:
10 
11     CADOHelper(void);
12     ~CADOHelper(void);
13     CString GetConnString();
14     void SetConnString(CString _conn);
15     void InitADOConn();
16     _RecordsetPtr& OpenRecordset(CString sql);
17     void CloseRecordset();
18     void CloseConn();
19     UINT GetRecordCount(_RecordsetPtr pRecordset);
20 };

实现文件ADOHelper.cpp

ADOHelper.CPP 
 1 #include "StdAfx.h"
 2 #include "ADOHelper.h"
 3 
 4 
 5 CADOHelper::CADOHelper(void):connStr()
 6 {
 7     
 8 }
 9 CString CADOHelper::GetConnString()
10 {
11     return connStr;
12 }
13 void CADOHelper::SetConnString(CString _conn)
14 {
15     connStr=_conn;
16 }
17 CADOHelper::~CADOHelper(void)
18 {
19 }
20 void CADOHelper::InitADOConn()
21 {
22     ::CoInitialize(NULL);
23     try
24     {
25         m_pConnection.CreateInstance("ADODB.Connection");
26         _bstr_t strConn=connStr;
27         m_pConnection->Open(strConn,"","",adModeUnknown);
28     }
29     catch    (_com_error ex)
30     {
31         AfxMessageBox(ex.Description());
32     }
33 }
34 _RecordsetPtr& CADOHelper::OpenRecordset(CString sql)
35 {
36     ASSERT(!sql.IsEmpty());
37     try
38     {
39         m_pRecordset.CreateInstance(_uuidof(Recordset));
40         m_pRecordset->Open(_bstr_t(sql),m_pConnection.GetInterfacePtr(),adOpenDynamic,adLockOptimistic,adCmdText);
41     }
42     catch (_com_error e)
43     {
44         AfxMessageBox(e.Description());
45     }
46     return m_pRecordset;
47 }
48 void CADOHelper::CloseRecordset()
49 {
50     if (m_pRecordset->GetState()==adStateOpen)
51     {
52         m_pRecordset->Close();
53     }
54 }
55 void CADOHelper::CloseConn()
56 {
57     m_pConnection->Close();
58     ::CoUninitialize();
59 }
60 UINT CADOHelper::GetRecordCount(_RecordsetPtr pRecordset)
61 {
62     int nCount=0;
63     try
64     {
65         pRecordset->MoveFirst();
66 
67     }
68     catch (...)
69     {
70         return 0;
71     }
72     if (pRecordset->adoBOF)
73     {
74         return 0;
75     }
76     while(!pRecordset->adoEOF)
77     {
78         pRecordset->MoveNext();
79         nCount++;
80 
81     }
82     pRecordset->MoveFirst();
83     return nCount;
84 }

 

4.在OnInitDialog方法中添加如下代码，查询并显示用户表的Users数据

 1 m_listctrl.InsertColumn(0,L"ID",LVCFMT_LEFT,130,0);
 2     m_listctrl.InsertColumn(1,L"姓名",LVCFMT_LEFT,130,1);
 3     m_listctrl.InsertColumn(2,L"密码",LVCFMT_LEFT,130,2);
 4     m_listctrl.InsertItem(0,L"");
 5     m_listctrl.SetItemText(0,0,L"guanyu");
 6     m_listctrl.SetItemText(0,1,L"guanyu");
 7     m_listctrl.InsertItem(1,L"");
 8     m_listctrl.SetItemText(1,0,L"guanyu");
 9     m_listctrl.SetItemText(1,1,L"guanyu");
10     
11     /*CADOHelper m_pAdoHelper;
12     m_pAdoHelper.SetConnString(L"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\\我的文档\\Visual Studio 2010\\Projects\\MineGeology\\MineGeology\\AppData\\Geology.mdb;Persist Security Info=False");
13     m_pAdoHelper.InitADOConn();
14     CString sql("select * from Users");
15     m_pAdoHelper.m_pRecordset=m_pAdoHelper.OpenRecordset(sql);
16     int i=1;
17     while(!m_pAdoHelper.m_pRecordset->adoEOF)
18     {
19         i++;
20         m_listctrl.InsertItem(0,L"");
21         m_listctrl.SetItemText(0,0,(_bstr_t)m_pAdoHelper.m_pRecordset->GetCollect("ID"));
22         m_listctrl.SetItemText(0,1,(_bstr_t)m_pAdoHelper.m_pRecordset->GetCollect("User_Name"));
23         m_listctrl.SetItemText(0,2,(_bstr_t)m_pAdoHelper.m_pRecordset->GetCollect("Pwd"));
24         m_pAdoHelper.m_pRecordset->MoveNext();
25     }
26     m_pAdoHelper.CloseRecordset();
27     m_pAdoHelper.CloseConn();*/
28     CADOHelper* m_pAdoHelper=new CADOHelper();
29     m_pAdoHelper->SetConnString(L"Provider=Microsoft.Jet.OLEDB.4.0;Data Source=E:\\我的文档\\Visual Studio 2010\\Projects\\MineGeology\\MineGeology\\AppData\\Geology.mdb;Persist Security Info=False");
30     m_pAdoHelper->InitADOConn();
31     CString sql("select * from Users");
32     m_pAdoHelper->m_pRecordset=m_pAdoHelper->OpenRecordset(sql);
33     int i=1;
34     while(!m_pAdoHelper->m_pRecordset->adoEOF)
35     {
36         i++;
37         m_listctrl.InsertItem(0,L"");
38         m_listctrl.SetItemText(0,0,(_bstr_t)m_pAdoHelper->m_pRecordset->GetCollect("ID"));
39         m_listctrl.SetItemText(0,1,(_bstr_t)m_pAdoHelper->m_pRecordset->GetCollect("User_Name"));
40         m_listctrl.SetItemText(0,2,(_bstr_t)m_pAdoHelper->m_pRecordset->GetCollect("Pwd"));
41         m_pAdoHelper->m_pRecordset->MoveNext();
42     }
43     m_pAdoHelper->CloseRecordset();
44     m_pAdoHelper->CloseConn();
45     delete m_pAdoHelper;

代码中注释部分为类对象的访问方式，使用中的为动态内存访问方式。

posted @ 2012-12-01 10:25  太一吾鱼水  阅读(414)  评论(0)  编辑  收藏  举报