为什么该程序无法获取数据 [英] Why the data is not fetching by this program

问题描述

为什么该程序无法获取数据.我只想获取四列数据，这些数据在所有数据点中最大.

错误-索引超出范围未由用户处理

错误行是-TextBox4.Text = dRow.ItemArray.GetValue(4).ToString();

我的CS涂层下面给出了

Why the data is not fetching by this program.I want to fetch only four columns data which points is greatest among all points.

ERROR- Index Out Of Range was unhandled by user

Error Line is - TextBox4.Text = dRow.ItemArray.GetValue(4).ToString();

My CS COADING IS GIVEN BELOW

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data.OleDb;
using System.Data;


public partial class Retrive_Data_From_Database_and_display_in_TextBox : System.Web.UI.Page
{
    OleDbConnection con;
    OleDbCommand com;
    OleDbDataAdapter da;
    DataSet ds;
    protected void Page_Load(object sender, EventArgs e)
    {
        con = new System.Data.OleDb.OleDbConnection();
        ds = new DataSet();
        con.ConnectionString = "PROVIDER=Microsoft.Jet.OLEDB.4.0;Data Source=" + Server.MapPath("~/kamnagroup.mdb") + "";
        string sql = "select aname,add1,photo,point from joining WHERE point=(SELECT MAX(point) FROM joining)";
        da = new System.Data.OleDb.OleDbDataAdapter(sql,con);
        con.Open();
        da.Fill(ds,"joining");
        navigatedata();
        con.Close();
        con.Dispose();
    }
    private void navigatedata()
    {
        DataRow dRow=ds.Tables["joining"].Rows[0];
        
        TextBox1.Text = dRow.ItemArray.GetValue(1).ToString();
        TextBox2.Text = dRow.ItemArray.GetValue(2).ToString();
        TextBox3.Text = dRow.ItemArray.GetValue(3).ToString();
        TextBox4.Text = dRow.ItemArray.GetValue(4).ToString();
        Image1.ImageUrl = TextBox3.Text;
        
    }
}

推荐答案

//正确的代码是.........

//Correct code is.........

private void navigatedata()
      {
            DataRow dRow=ds.Tables["joining"].Rows[0];

            TextBox1.Text = dRow.ItemArray.GetValue(0).ToString();
            TextBox2.Text = dRow.ItemArray.GetValue(1).ToString();
            TextBox3.Text = dRow.ItemArray.GetValue(2).ToString();
            TextBox4.Text = dRow.ItemArray.GetValue(3).ToString();
            Image1.ImageUrl = TextBox3.Text;

      }

< pre lang ="c#">

私有void navigationdata()
{
DataRow dRow = ds.Tables ["joining"].Rows [0];

TextBox1.Text = dRow [0] .ToString();
TextBox2.Text = dRow [1] .ToString();
TextBox3.Text = dRow [2] .ToString();
TextBox4.Text = dRow [3] .ToString();
Image1.ImageUrl = TextBox3.Text;

}
</pre>
试试这个，我确定它会起作用..:)

<pre lang="c#">

private void navigatedata()
{
DataRow dRow=ds.Tables["joining"].Rows[0];

TextBox1.Text = dRow[0].ToString();
TextBox2.Text = dRow[1].ToString();
TextBox3.Text = dRow[2].ToString();
TextBox4.Text = dRow[3].ToString();
Image1.ImageUrl = TextBox3.Text;

}
</pre>
Try this I am sure this will work.. :)

每次调用GetValue(x)返回的值是什么，是否有效?另外，Image1.ImageUrl中存储的值是多少?尝试使用调试器来逐步检查代码，并在检查每个值时准确查看其失败原因.仅仅说不起作用"并不是一个非常有用的注释.

What is the value returned by each call to GetValue(x), is it valid or not? Also what is the value stored in Image1.ImageUrl? Try using your debugger to step through the code and check each value as you go to see exactly why it is failing. Just saying "not working" is not a very useful comment.

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