异常详细信息: System.InvalidOperationException: ConnectionString 属性尚未初始化。源错误:
行 100: SqlConnection myConnection = new SqlConnection();
行 101: SqlCommand myCommand = new SqlCommand(updateCmd,myConnection);
行 102: myCommand.Connection.Open();
行 103: try
行 104: {
行 100: SqlConnection myConnection = new SqlConnection();
行 101: SqlCommand myCommand = new SqlCommand(updateCmd,myConnection);
行 102: myCommand.Connection.Open();
行 103: try
行 104: {
大哥帮我解决了,我另开帖子送分。string strconn="server=localhost;uid=sa;pwd=;database=keyan";
string strUpdate="";
strUpdate+="xm='"+((TextBox)e.Item.Cells[1].Controls[0]).Text+"'";
strUpdate+=",xb='"+((TextBox)e.Item.Cells[2].Controls[0]).Text+"'";
strUpdate+=",mz='"+((TextBox)e.Item.Cells[3].Controls[0]).Text+"'";
strUpdate+=",zzmm='"+((TextBox)e.Item.Cells[4].Controls[0]).Text+"'";
strUpdate+=",zc='"+((TextBox)e.Item.Cells[5].Controls[0]).Text+"'";
strUpdate+=",szbm='"+((TextBox)e.Item.Cells[6].Controls[0]).Text+"'";
string updateCmd="Update Teacher set "+strUpdate+" where xm like '"+((TextBox)e.Item.Cells[1].Controls[0]).Text+"'";
SqlConnection myConnection = new SqlConnection();
myConnection.ConnectionString=strconn;
SqlCommand myCommand = new SqlCommand(updateCmd,myConnection);
myCommand.Connection.Open();
try
{
myCommand.ExecuteNonQuery();
DataGrid1.EditItemIndex=-1;
Response.Write("<script language='javascript'>alert('更新记录成功!')</script>");
}
catch
{
Response.Write("<script language='javascript'>alert('未能更新记录,请确保正确填写了字段!')</script>");
}
DataGrid1.DataBind();
一般来说DG要绑定DataSet中的,你要通过改变DataSet才可以修改数据!
using System ;
using System.Drawing ;
using System.ComponentModel ;
using System.Windows.Forms ;
using System.Data.OleDb ;
using System.Data ;public class Data : Form
{
private System.ComponentModel.Container components = null ;
private Button lastrec ;
private Button nextrec ;
private Button previousrec ;
private Button firstrec ;
private TextBox t_books ;
private TextBox t_nl ;
private ComboBox t_xb ;
private TextBox t_xm ;
private TextBox t_id ;
private Label l_books ;
private Label l_nl ;
private Label l_xb ;
private Label l_xm ;
private Label l_id ;
private Label label1 ;
private DataSet myDataSet ;
private Button button1 ;
private Button button2 ;
private Button button3 ;
private Button button4 ;
private BindingManagerBase myBind ; public Data ( )
{
file://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 ( ) ;
}
file://清除在程序中使用过的资源
protected override void Dispose( bool disposing )
{
if( disposing )
{
if ( components != null )
{
components.Dispose ( ) ;
}
}
base.Dispose( disposing ) ;
}
public static void Main ( )
{
Application.Run ( new Data ( ) ) ;
}
public void GetConnected ( )
{
try
{
file://创建一个 OleDbConnection
string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;
OleDbConnection myConn = new OleDbConnection ( strCon ) ;
string strCom = " SELECT * FROM person " ;
file://创建一个 DataSet
myDataSet = new DataSet ( ) ;myConn.Open ( ) ;
file://用 OleDbDataAdapter 得到一个数据集
OleDbDataAdapter myCommand = new OleDbDataAdapter ( strCom , myConn ) ;
file://把Dataset绑定books数据表
myCommand.Fill ( myDataSet , "person" ) ;
file://关闭此OleDbConnection
myConn.Close ( ) ;
}
catch ( Exception e )
{
MessageBox.Show ( "连接错误! " + e.ToString ( ) , "错误" ) ;
}
}
private void InitializeComponent ( )
{file://添加控件,略this.Name = "Data" ;
this.Text = "Visual C#的数据库编程!" ;
this.ResumeLayout(false) ;
myBind = this.BindingContext [ myDataSet , "person" ] ;
}
protected void New_record ( object sender , System.EventArgs e )
{t_id.Text = ( myBind.Count + 1 ).ToString ( ) ;
t_xm.Text = "" ;
t_xb.Text = "" ;
t_nl.Text = "" ;
t_books.Text = "" ;}
protected void Insert_record ( object sender , System.EventArgs e )
{
try
{
file://判断所有字段是否添完,添完则执行,反之弹出提示
if ( t_id.Text != "" && t_xm.Text != "" && t_xb.Text != "" && t_nl.Text != "" && t_books.Text != "" )
{
string myConn1 = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb" ;
OleDbConnection myConn = new OleDbConnection ( myConn1 ) ;
myConn.Open ( ) ;
string strInsert = " INSERT INTO person ( id , xm , xb , nl , zip ) VALUES ( " ;
strInsert += t_id.Text + ", '" ;
strInsert += t_xm.Text + "', '" ;
strInsert += t_xb.Text + "', " ;
strInsert += t_nl.Text + ", " ;
strInsert += t_books.Text + ")" ;
OleDbCommand inst = new OleDbCommand ( strInsert , myConn ) ;
inst.ExecuteNonQuery ( ) ;
myConn.Close ( ) ;
myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;
myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;
myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;
}
else
{
MessageBox.Show ( "必须填满所有字段值!" , "错误!" ) ;
}
}
catch ( Exception ed )
{
MessageBox.Show ( "保存数据记录发生 " + ed.ToString ( ) , "错误!" ) ;
}
}protected void Update_record ( object sender , System.EventArgs e )
{
int i = myBind.Position ;
try{
file://连接到一个数据库
string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb " ;
OleDbConnection myConn = new OleDbConnection ( strCon ) ;
myConn.Open ( ) ;
myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . BeginEdit ( ) ;
file://从数据库中修改指定记录
string strUpdt = " UPDATE person SET xm = '"
+ t_xm.Text + "' , xb = '"
+ t_xb.Text + "' , nl = "
+ t_nl.Text + " , zip = "
+ t_books.Text + " WHERE id = " + t_id.Text ;
OleDbCommand myCommand = new OleDbCommand ( strUpdt , myConn ) ;
myCommand.ExecuteNonQuery ( ) ;
myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . EndEdit ( ) ;
myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;
myConn.Close ( ) ;
}
catch ( Exception ed )
{
MessageBox.Show ( "修改指定记录错误: " + ed.ToString ( ) , "错误!" ) ;
}
myBind.Position = i ;
}
protected void Delete_record ( object sender , System.EventArgs e )
{
DialogResult r = MessageBox.Show ( "是否删除当前记录!" , "删除当前记录!" , MessageBoxButtons.YesNo , MessageBoxIcon.Question ) ;
int ss = ( int ) r ;
if ( ss == 6 ) // 按动"确定"按钮
{
try{
file://连接到一个数据库
string strCon = " Provider = Microsoft.Jet.OLEDB.4.0 ; Data Source = db.mdb " ;
OleDbConnection myConn = new OleDbConnection ( strCon ) ;
myConn.Open ( ) ;
string strDele = "DELETE FROM person WHERE id= " + t_id.Text ;
OleDbCommand myCommand = new OleDbCommand ( strDele , myConn ) ;
file://从数据库中删除指定记录
myCommand.ExecuteNonQuery ( ) ;
file://从DataSet中删除指定记录
myDataSet.Tables [ "person" ] . Rows [ myBind.Position ] . Delete ( ) ;
myDataSet.Tables [ "person" ] . AcceptChanges ( ) ;
myConn.Close ( ) ;
}
catch ( Exception ed )
{
MessageBox.Show ( "删除记录错误信息: " + ed.ToString ( ) , "错误!" ) ;
}
}
}file://按钮"尾记录"对象事件程序
protected void GoLast ( object sender , System.EventArgs e )
{
myBind.Position = myBind.Count - 1 ;
}file://按钮"下一条"对象事件程序
protected void GoNext ( object sender , System.EventArgs e )
{
if ( myBind.Position == myBind.Count -1 )
MessageBox.Show ( "已经到了最后一条记录!", "信息提示!" , MessageBoxButtons.OK , MessageBoxIcon.Information ) ;
else
myBind.Position += 1 ;
}
file://按钮"上一条"对象事件程序
protected void GoPrevious ( object sender , System.EventArgs e )
{
if ( myBind.Position == 0 )
MessageBox.Show ( "已经到了第一条记录!" , "信息提示!" , MessageBoxButtons.OK , MessageBoxIcon.Information ) ;
else
myBind.Position -= 1 ;
}
file://按钮"首记录"对象事件程序
protected void GoFirst ( object sender , System.EventArgs e )
{
myBind.Position = 0 ;
}
}
注:来源Yesky
在catch块中这样写
catch(Exception ex)
{
MessageBox .Show(ex.Message);
}
能得到你的错误信息