用VisualC#中轻松浏览数据库记录

1、用 Visual C#中轻松浏览数据库记录一、 程式的主要功能介绍:程式打开本地 Acess 数据库(sample.mdb 中的 book 数据表,然后把 book 数据表中的字段绑定到程式提供的文本框中,显示出来。通过程式中的四个按钮 " 首记录 " 、 " 尾记录 " 、 " 上一条 " 、 " 下 一条 " ,实现对 book 数据表中的记录浏览。程式的运行界面如下:图 01:对数据表中记录浏览程式的运行界面二、程式设计和运行的环境设置:(1视窗 2000服务器版(2 Microsoft Acess Data

2、 Component 2.6 ( MADC 2.6 三、程式设计难点和应该注意的问题:(1怎么实现把数据表中的字段用文本框来显示:如果直接把字段的值赋值给文本框,这时如果用 " 下一条 " 等按钮来浏览数据记录的时候,文本框的值是不 会变化的。怎么让文本框根据数据表中的记录指针来动态的显示要字段值,这是本文的一个重点,也是个 难点。本文是通过把数据表中的字段值绑定到文本框的 "Text" 属性上,来实现动态显示字段数值的。实现这种处 理要用到文本框的 DataBindings 属性和其中的 Add 方法。具体语法如下:文本组件名称 .DataBindin

3、gs.Add ( "Text" , DataSet对象 , 数据表和字段名称 ;在程式具体如下:t_bookid.DataBindings.Add ( "Text" , myDataSet , "books.bookid" ;这样就能根据记录指针来实现要显示的字段值了。(2怎么改动记录指针:只有掌控怎么改动记录指针,才能随心所欲的浏览记录。 Visual C#改动记录指针是通过一个命叫BindingManagerBase 对象来实现的。此对象封装在名称空间 System. 视窗系统 .Froms 中。BindingManagerBas

4、e 对象是个抽象的对象,管理所有绑定的同类的数据源和数据成员。在程式设计中主 要用到 BindingManagerBase 对象中的二个属性,即:Position 属性和 Count 属性。第一个属性是记录了 数据集的当前指针,后一个属性是当前数据集中的记录总数。由此能得到改动记录指针的四个按钮对应的 程式代码:i>.首记录:myBind.Position = 0 ;ii>.尾记录:myBind.Position = myBind.Count - 1 ;iii>.下一条记录和操作后运行界面:if ( myBind.Position = myBind.Count -1 Mess

5、ageBox.Show ( "已到了最后一条记录! " ;elsemyBind.Position += 1 ;iV>.上一条记录和操作后运行界面:if ( myBind.Position = 0 MessageBox.Show ( "已到了第一条记录! " ;elsemyBind.Position -= 1 ;四 . 程式原始码 :using System ;using System.Drawing ;using System.ComponentModel ;using System.视窗系统 .Forms ;using System.Data.O

6、leDb ;using System.Data ;public class DataView : Form private System.ComponentModel.Container components ; private Button lastrec ;private Button nextrec ;private Button previousrec ;private Button firstrec ;private TextBox t_books ;private TextBox t_bookprice ;private TextBox t_bookauthor ;private

7、TextBox t_booktitle ;private TextBox t_bookid ;private Label l_books ;private Label l_bookprice ;private Label l_bookauthor ;private Label l_booktitle ;private Label l_bookid ;private Label label1 ;private System.Data.DataSet myDataSet ;private BindingManagerBase myBind ;public DataView ( /连接到一个数据库G

8、etConnected ( ;/ 对窗体中所需要的内容进行初始化InitializeComponent ( ;public override void Dispose ( base.Dispose ( ;components.Dispose ( ;public static void Main ( Application.Run ( new DataView ( ;public void GetConnected ( try/创建一个 OleDbConnectionstring strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data

9、Source = sample.mdb" ; OleDbConnection myConn = new OleDbConnection ( strCon ;string strCom = " SELECT * FROM books " ;/创建一个 DataSetmyDataSet = new DataSet ( ;myConn.Open ( ;/用 OleDbDataAdapter 得到一个数据集OleDbDataAdapter myCommand = new OleDbDataAdapter ( strCom , myConn ; /把 Dataset 绑定

10、books 数据表myCommand.Fill ( myDataSet , "books" ;/关闭此 OleDbConnectionmyConn.Close ( ;catch ( Exception e MessageBox.Show ( "连接错误 ! " + e.ToString ( , "错误 " ; private void InitializeComponent ( ponents = new System.ComponentModel.Container ( ; this.t_bookid = new TextBox (

11、 ;this.nextrec = new Button ( ;this.lastrec = new Button ( ;this.l_bookid = new Label ( ;this.t_books = new TextBox ( ;this.t_booktitle = new TextBox ( ;this.t_bookprice = new TextBox ( ;this.firstrec = new Button ( ;this.l_booktitle = new Label ( ;this.l_bookprice = new Label ( ;this.l_books = new

12、Label ( ;this.previousrec = new Button ( ;this.l_bookauthor = new Label ( ;this.t_bookauthor = new TextBox ( ;this.label1 = new Label ( ;/以下是对数据浏览的四个按钮进行初始化firstrec.Location = new System.Drawing.Point ( 55 , 312 ; firstrec.ForeColor = System.Drawing.Color.Black ;firstrec.Size = new System.Drawing.Si

13、ze ( 40 , 24 ;firstrec.TabIndex = 5 ;firstrec.Font = new System.Drawing.Font("仿宋 ", 8f ;firstrec.Text = "首记录 "firstrec.Click += new System.EventHandler(GoFirst;previousrec.Location = new System.Drawing.Point ( 125 , 312 ; previousrec.ForeColor = System.Drawing.Color.Black ;previo

14、usrec.Size = new System.Drawing.Size(40, 24 ;previousrec.TabIndex = 6 ;previousrec.Font = new System.Drawing.Font ( "仿宋 " , 8f ; previousrec.Text = "上一条 " ;previousrec.Click += new System.EventHandler ( GoPrevious ;nextrec.Location = new System.Drawing.Point ( 195 , 312 ;nextrec.

15、ForeColor = System.Drawing.Color.Black ;nextrec.Size = new System.Drawing.Size ( 40 , 24 ;nextrec.TabIndex = 7 ;nextrec.Font = new System.Drawing.Font ( "仿宋 " , 8f ;nextrec.Text = "下一条 " ;nextrec.Click += new System.EventHandler ( GoNext ;lastrec.Location = new System.Drawing.Poi

16、nt ( 265 , 312 ;lastrec.ForeColor = System.Drawing.Color.Black ;lastrec.Size = new System.Drawing.Size ( 40 , 24 ;lastrec.TabIndex = 8 ;lastrec.Font = new System.Drawing.Font ( "仿宋 " , 8f ;lastrec.Text = "尾记录 " ;lastrec.Click += new System.EventHandler ( GoLast ;/以下是对为显示数据记录而设定的标

17、签和文本框进行初始化,并把记录绑定在不同的绑定到文本框 "Text" 属性上t_bookid.Location = new System.Drawing.Point ( 184 , 56 ;t_bookid.TabIndex = 9 ;t_bookid.Size = new System.Drawing.Size ( 80 , 20 ;t_bookid.DataBindings.Add ( "Text" , myDataSet , "books.bookid" ;t_books.Location = new System.Drawin

18、g.Point ( 184 , 264 ;t_books.TabIndex = 10 ;t_books.Size = new System.Drawing.Size ( 80 , 20 ;t_books.DataBindings.Add ( "Text" , myDataSet , "books.bookstock" ;t_booktitle.Location = new System.Drawing.Point ( 184 , 108 ;t_booktitle.TabIndex = 11 ;t_booktitle.Size = new System.D

19、rawing.Size ( 176 , 20 ;t_booktitle.DataBindings.Add( "Text" , myDataSet , "books.booktitle" ;t_bookprice.Location = new System.Drawing.Point ( 184 , 212 ;t_bookprice.TabIndex = 12 ;t_bookprice.Size = new System.Drawing.Size ( 80 , 20 ;t_bookprice.DataBindings.Add ( "Text&qu

20、ot; , myDataSet , "books.bookprice" ;t_bookauthor.Location = new System.Drawing.Point ( 184 , 160 ; t_bookauthor.TabIndex = 18 ; t_bookauthor.Size = new System.Drawing.Size ( 128 , 20 ; t_bookauthor.DataBindings.Add ( "Text" , myDataSet , "books.bookauthor" ; l_bookid.L

21、ocation = new System.Drawing.Point ( 24 , 56 ; l_bookid.Text = "书本序号：" ; l_bookid.Size = new System.Drawing.Size ( 112, 20 ; l_bookid.Font = new System.Drawing.Font ( "仿宋" , 10f ; l_bookid.TabIndex = 13 ; l_bookid.TextAlign = System.Drawing.ContentAlignment.MiddleCenter ; l_bookt

22、itle.Location = new System.Drawing.Point ( 24 , 108 ; l_booktitle.Text = "书 名：" l_booktitle.Size = new System.Drawing.Size ( 112 , 20 ; l_booktitle.Font = new System.Drawing.Font ( "仿宋" , 10f ; l_booktitle.TabIndex = 14 ; l_booktitle.TextAlign = System.Drawing.ContentAlignment.Mi

23、ddleCenter ; l_bookprice.Location = new System.Drawing.Point ( 24 , 212 ; l_bookprice.Text = "价 格：" ; l_bookprice.Size = new System.Drawing.Size ( 112 , 20 ; l_bookprice.Font = new System.Drawing.Font ( "仿宋" , 10f ; l_bookprice.TabIndex = 15 ; l_bookprice.TextAlign = System.Drawi

24、ng.ContentAlignment.MiddleCenter ; l_books.Location = new System.Drawing.Point ( 24 , 264 ; l_books.Text = "书 架 号：" ; l_books.Size = new System.Drawing.Size ( 112 , 20 ; l_books.Font = new System.Drawing.Font ( "仿宋" , 10f ; l_books.TabIndex = 16 ; l_books.TextAlign = System.Drawi

25、ng.ContentAlignment.MiddleCenter ; l_bookauthor.Location = new System.Drawing.Point ( 24 , 160 ; l_bookauthor.Text = "作 者：" ; l_bookauthor.Size = new System.Drawing.Size ( 112 , 20 ; l_bookauthor.Font = new System.Drawing.Font ( "仿宋" , 10f ; l_bookauthor.TabIndex = 17 ; l_bookaut

26、hor.TextAlign = System.Drawing.ContentAlignment.MiddleCenter ; label1.Location = new System.Drawing.Point ( 49 , 8 ; label1.Text = "浏览书籍信息" ; label1.Size = new System.Drawing.Size ( 296 , 24 ; label1.ForeColor = System.Drawing.Color.Green ; label1.Font = new System.Drawing.Font ( "仿宋&

27、quot; , 15f ; label1.TabIndex = 19 ; /对窗体进行设定 this.Text = "用 C#做浏览数据库中记录的程式！" this.AutoScaleBaseSize = new System.Drawing.Size ( 5 , 13 ; this.FormBorderStyle = FormBorderStyle.FixedSingle ; this.ClientSize = new System.Drawing.Size ( 394 , 375 ; /在窗体中加入组件 this.Controls.Add ( lastrec ; thi

28、s.Controls.Add ( nextrec ; this.Controls.Add ( previousrec ; this.Controls.Add ( firstrec ; this.Controls.Add ( t_books ; this.Controls.Add ( t_bookprice ; this.Controls.Add ( t_bookauthor ; this.Controls.Add ( t_booktitle ; this.Controls.Add ( t_bookid ; this.Controls.Add ( l_books ; this.Controls.Add ( l_bookprice ; this.Controls.Add ( l_bookautho