请教关于在datagrid中更新的问题。

string colvalue=((TextBox)e.Item.Cells[i].Controls[0]).Text;
请注意,你的控件未必是Controls[0],如果你在前台的代码中有回车符或空格等符号
你要找的控件就可以变成string colvalue=((TextBox)e.Item.Cells[i].Controls[1]).Text;
建议你改成1试试

解决方案 »

免费领取超大流量手机卡，每月29元包185G流量+100分钟通话, 中国电信官方发货

如果无法确定的话,最好使用函数gettype(),通过返回值确定控件的类型,这个问题是经常会遇到的,多写了就会好的!!
我把0改成1了，可是出现下面的错误：
System.ArgumentOutOfRangeException: 指定的参数已超出有效值的范围。参数名：index
楼上说的话我看不懂，我刚学c#，菜鸟一个。
楼主你编辑的时候是否每一列都有textbox存在?
看你的情况是有没有txtbox存在的列,而你是遍历所有列,
这时候有的列没有取到,所以出错(出了这个新的错误说明不是前面我分析的原因)
我显示出来的所有列都有textbox啊！当然我有个列就是Xdwzhh_id，我没有让它显示出来也没设置textbox，可它是最后一列阿！我的代码没有去弄最后一列的啊！因为循环条件设置了i<numCols-1
楼主把前台的DataGrid部分的代码贴出来!!
前台代码指什么？我什么html源代码么？我先贴html这个把~不知道是不是<%@ Page language="c#" Codebehind="dwzhhxx_bj.aspx.cs" AutoEventWireup="false" Inherits="WebApplication1.shiyan" %>
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN" >
<HTML>
<HEAD>
<title>shiyan</title>
<meta content="Microsoft Visual Studio 7.0" name="GENERATOR">
<meta content="C#" name="CODE_LANGUAGE">
<meta content="JavaScript" name="vs_defaultClientScript">
<meta content="http://schemas.microsoft.com/intellisense/ie5" name="vs_targetSchema">
</HEAD>
<body bgColor="#6600ff" MS_POSITIONING="GridLayout">
<form id="shiyan" method="post" runat="server">
<FONT face="宋体">
<asp:panel id="Panel1" style="Z-INDEX: 104; LEFT: 16px; POSITION: absolute; TOP: 86px" runat="server" BackColor="#6600FF" HorizontalAlign="Center" ForeColor="InfoText" Font-Size="X-Large" Width="500px" Height="30px">单位帐户信息
</asp:panel><asp:button id="Button1" style="Z-INDEX: 102; LEFT: 440px; POSITION: absolute; TOP: 62px" runat="server" Width="60px" Height="20px" BorderStyle="Outset" Text="开始查找"></asp:button><asp:textbox id="TextBox1" style="Z-INDEX: 101; LEFT: 307px; POSITION: absolute; TOP: 60px" runat="server" Width="120px" Height="20px"></asp:textbox><asp:datagrid id="DataGrid1" style="Z-INDEX: 103; LEFT: 18px; POSITION: absolute; TOP: 126px" runat="server" BackColor="White" Width="500px" Height="150px" BorderStyle="None" CellPadding="4" BorderWidth="1px" BorderColor="#CC9966" AutoGenerateColumns="False" PageSize="5" AllowPaging="True">
<SelectedItemStyle Font-Bold="True" ForeColor="#663399" BackColor="#FFCC66"></SelectedItemStyle>
<ItemStyle ForeColor="#330099" BackColor="White"></ItemStyle>
<HeaderStyle Font-Bold="True" ForeColor="#FFFFCC" BackColor="#990000"></HeaderStyle>
<FooterStyle ForeColor="#330099" BackColor="#FFFFCC"></FooterStyle>
<Columns>
<asp:BoundColumn DataField="dwdm" HeaderText="单位代码"></asp:BoundColumn>
<asp:BoundColumn DataField="bh" HeaderText="编号"></asp:BoundColumn>
<asp:BoundColumn DataField="mch" HeaderText="名称"></asp:BoundColumn>
<asp:BoundColumn DataField="shbjg" HeaderText="社保机构"></asp:BoundColumn>
<asp:BoundColumn DataField="khyh" HeaderText="开户银行"></asp:BoundColumn>
<asp:BoundColumn DataField="yhzhh" HeaderText="银行账号"></asp:BoundColumn>
<asp:BoundColumn DataField="frdb" HeaderText="法人代表"></asp:BoundColumn>
<asp:BoundColumn DataField="lxr" HeaderText="联系人"></asp:BoundColumn>
<asp:EditCommandColumn ButtonType="LinkButton" UpdateText="更新" CancelText="取消" EditText="编辑"></asp:EditCommandColumn>
<asp:ButtonColumn Text="删除" CommandName="Delete"></asp:ButtonColumn>
</Columns>
<PagerStyle HorizontalAlign="Center" ForeColor="#330099" BackColor="#FFFFCC"></PagerStyle>
</asp:datagrid><asp:label id="Label1" style="Z-INDEX: 105; LEFT: 77px; POSITION: absolute; TOP: 61px" runat="server" Width="55px" Height="22px">请选择</asp:label><asp:dropdownlist id="DropDownList1" style="Z-INDEX: 106; LEFT: 146px; POSITION: absolute; TOP: 61px" runat="server" Width="155px" Height="20px">
<asp:ListItem Value="1">单位代码</asp:ListItem>
<asp:ListItem Value="2">编号</asp:ListItem>
<asp:ListItem Value="3">名称</asp:ListItem>
<asp:ListItem Value="4">社保机构</asp:ListItem>
<asp:ListItem Value="5">开户银行</asp:ListItem>
<asp:ListItem Value="6">银行账号</asp:ListItem>
<asp:ListItem Value="7">法人代表</asp:ListItem>
<asp:ListItem Value="8">联系人</asp:ListItem>
</asp:dropdownlist><asp:label id="Label2" style="Z-INDEX: 107; LEFT: 82px; POSITION: absolute; TOP: 11px" runat="server" ForeColor="Red" Width="420px" Height="44px" Visible="False">Label</asp:label></FONT></form>
</body>
</HTML>
干脆我把所有的代码都贴出来吧
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;namespace WebApplication1
{
/// <summary>
/// shiyan 的摘要说明。
/// </summary>
public class shiyan : System.Web.UI.Page
{
protected System.Web.UI.WebControls.TextBox TextBox1;
protected System.Web.UI.WebControls.Button Button1;
protected System.Web.UI.WebControls.DataGrid DataGrid1;
protected System.Data.SqlClient.SqlConnection sqlConnection1;
protected System.Web.UI.WebControls.Panel Panel1;
protected System.Web.UI.WebControls.Label Label1;
protected System.Web.UI.WebControls.Label Label2;
protected System.Web.UI.WebControls.DropDownList DropDownList1;

private void Page_Load(object sender, System.EventArgs e)
{
if (!IsPostBack)
BindGrid();
} #region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN：该调用是 ASP.NET Web 窗体设计器所必需的。
//
InitializeComponent();
base.OnInit(e);
}

/// <summary>
/// 设计器支持所需的方法 - 不要使用代码编辑器修改
/// 此方法的内容。
/// </summary>
private void InitializeComponent()
{
this.sqlConnection1 = new System.Data.SqlClient.SqlConnection();
this.Button1.Click += new System.EventHandler(this.Button1_Click);
this.DataGrid1.CancelCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_CancelCommand);
this.DataGrid1.EditCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_EditCommand);
this.DataGrid1.UpdateCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_UpdateCommand);
this.DataGrid1.DeleteCommand += new System.Web.UI.WebControls.DataGridCommandEventHandler(this.DataGrid1_DeleteCommand);
//
// sqlConnection1
//
this.sqlConnection1.ConnectionString = "data source=localhost;password=sa;persist security info=True;user id=sa;workstati" +
"on id=YYL-013FE796E23;packet size=4096";
this.Load += new System.EventHandler(this.Page_Load); }
#endregion
string str1="select * from dwzhhxx where dwdm=@Id"; private void Button1_Click(object sender, System.EventArgs e)
{
string i=this.DropDownList1.SelectedItem.Value;
switch (i)
{
case "1":
str1="select * from dwzhhxx where dwdm=@Id";
break;
case "2":
str1="select * from dwzhhxx where bh=@Id";
break;
case "3":
str1="select * from dwzhhxx where mch=@Id";
break;
case "4":
str1="select * from dwzhhxx where shbjg=@Id";
break;
case "5":
str1="select * from dwzhhxx where khyh=@Id";
break;
case "6":
str1="select * from dwzhhxx where yhzhh=@Id";
break;
case "7":
str1="select * from dwzhhxx where frdb=@Id";
break;
case "8":
str1="select * from dwzhhxx where lxr=@Id";
break;
}
SqlDataAdapter myCommand = new SqlDataAdapter(str1, sqlConnection1);
myCommand.SelectCommand.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 10));
myCommand.SelectCommand.Parameters["@Id"].Value = this.TextBox1.Text.ToString().Trim();
DataSet ds = new DataSet();
myCommand.Fill(ds,"zxhh");
DataGrid1.DataSource= ds.Tables["zxhh"].DefaultView;
DataGrid1.DataBind();
} private void DataGrid1_CancelCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
this.DataGrid1.EditItemIndex=-1;
BindGrid();
} private void DataGrid1_EditCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
this.DataGrid1.EditItemIndex=e.Item.ItemIndex;
BindGrid();
} private void DataGrid1_UpdateCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
String updateCmd = "update dwzhhxx set dwdm= @Xdwdm, bh= @Xbh, mch= @Xmch, shbjg= @Xshbjg, khyh=@Xkhyh; yhzhh=@Xyhzhh; frdb=@Xfrdb; lxr=@Xlxr,dwzhh_id=@Xdwzhh_id";
SqlCommand myCommand = new SqlCommand(updateCmd,sqlConnection1); myCommand.Parameters.Add(new SqlParameter("@Xdwdm", SqlDbType.NVarChar, 10));
myCommand.Parameters.Add(new SqlParameter("@Xbh", SqlDbType.NVarChar, 10));
myCommand.Parameters.Add(new SqlParameter("@Xmch", SqlDbType.NVarChar, 20));
myCommand.Parameters.Add(new SqlParameter("@Xshbjg", SqlDbType.NVarChar,10));
myCommand.Parameters.Add(new SqlParameter("@Xkhyh", SqlDbType.NChar, 10));
myCommand.Parameters.Add(new SqlParameter("@Xyhzhh", SqlDbType.NVarChar, 20));
myCommand.Parameters.Add(new SqlParameter("@Xfrdb", SqlDbType.NChar, 10));
myCommand.Parameters.Add(new SqlParameter("@Xlxr", SqlDbType.NChar, 10));
myCommand.Parameters.Add(new SqlParameter("@Xdwzhh_id", SqlDbType.Int, 4));
myCommand.Parameters["@Xdwzhh_id"].Value = DataGrid1.DataKeys[(int)e.Item.ItemIndex]; String[] cols = {"@Xdwdm","@Xbh","@Xmch","@Xshbjg","@Xkhyh","@Xyhzhh","@Xfrdb","@Xlxr"};
    int numCols = e.Item.Cells.Count;
for (int i=1; i<9; i++)
{
string colvalue = ((TextBox)e.Item.Cells[i].Controls[0]).Text; // 检查在所需字段中是否有空值
if (colvalue.Equals(""))
{
this.Label2.Visible=true;
this.Label2.Text= "错误！修改项不允许使用空值";
return;
} myCommand.Parameters[cols[i-1]].Value = colvalue;
} myCommand.Connection.Open(); try
{
myCommand.ExecuteNonQuery();
this.Label2.Visible=true;
this.Label2.Text= "已更新记录";
DataGrid1.EditItemIndex = -1;
}
catch (SqlException exc)
{
if (exc.Number == 2627)
{
this.Label2.Visible=true;
this.Label2.Text= "错误：已存在具有相同主键的记录";
}
else
{
this.Label2.Visible=true;
this.Label2.Text= "错误：未能更新记录，请确保正确填写了字段";
}
} myCommand.Connection.Close(); BindGrid(); } public void BindGrid()
{
SqlDataAdapter myCommand = new SqlDataAdapter(str1, sqlConnection1);
myCommand.SelectCommand.Parameters.Add(new SqlParameter("@Id", SqlDbType.NVarChar, 10));
myCommand.SelectCommand.Parameters["@Id"].Value = this.TextBox1.Text.ToString().Trim();
DataSet ds = new DataSet();
myCommand.Fill(ds,"zxhh");
DataGrid1.DataSource= ds.Tables["zxhh"].DefaultView;
DataGrid1.DataKeyField="dwzhh_id";
DataGrid1.DataBind();
} private void DataGrid1_DeleteCommand(object source, System.Web.UI.WebControls.DataGridCommandEventArgs e)
{
String deleteCmd = "delete from dwzhhxx where dwzhh_id= @Sch"; SqlCommand myCommand = new SqlCommand(deleteCmd, sqlConnection1);
myCommand.Parameters.Add(new SqlParameter("@Sch", SqlDbType.NVarChar,11));
myCommand.Parameters["@Sch"].Value = DataGrid1.DataKeys[(int)e.Item.ItemIndex]; myCommand.Connection.Open(); try
{
myCommand.ExecuteNonQuery();
this.Label2.Visible=true;
this.Label2.Text= "已删除记录";
}
catch (SqlException)
{
this.Label2.Visible=true;
this.Label2.Text = "错误！未能删除记录";

} myCommand.Connection.Close(); BindGrid(); }
}
}