用Visual C#中轻松浏览数据库记录.docx

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 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.DataBindings.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。BindingManagerBase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 ) MessageBox.Show ( 已到了最后一条记录！ ) ; else myBind.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！ ) ; else myBind.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.OleDb ; 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 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 GetConnected ( ) ; / 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 OleDbConnection string strCon = Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = sample.mdb ; OleDbConnection myConn = new OleDbConnection ( strCon ) ; string strCom = SELECT * FROM books ; /创建一个 DataSet myDataSet = new DataSet ( ) ; myConn.Open ( ) ; /用 OleDbDataAdapter 得到一个数据集 OleDbDataAdapter myCommand = new OleDbDataAdapter ( strCom , myConn ) ; /把Dataset绑定books数据表 myCommand.Fill ( myDataSet , books ) ; /关闭此OleDbConnection myConn.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 ( ) ; 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 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.Size ( 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 ; previousrec.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.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.Point ( 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.Drawing.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.Drawing.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 , 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.Location = 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_booktitle.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.MiddleCenter ; 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.Drawing.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.Drawing.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_bookauthor.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 , 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 ) ; this.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_bookpr