datatable与dataset加二维数组实现

using System;
using System.Data;
using System.Configuration;
using System.Collections;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Data.SqlClient;
using System.Data.OleDb;

public partial class reader : System.Web.UI.Page
{
    const string connStr = "data source=127.0.0.1;user id=sa;password=***;initial catalog=***";
    SqlConnection conn;
    protected void Page_Load(object sender, EventArgs e)
    {
        
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        conn = new SqlConnection(connStr);
        string sql = "select * from t_type";
        
        SqlCommand cmd;
        cmd = conn.CreateCommand();
        
        
        cmd.CommandText = sql;
        conn.Open();
        SqlDataReader reader = cmd.ExecuteReader();//这个是为了循环的
        DataTable dataTable = new DataTable();
        dataTable.Load(reader);
        string[,] rdrString = new string[dataTable.Rows.Count, 2];
        for (int i = 0; i < dataTable.Rows.Count; i++)
        {
            for (int j = 0; j < 2; j++)
            {
                rdrString = dataTable.Rows[j].ToString();
            }
        }
        reader.Close();
        foreach (string temp in rdrString)
        {
            this.Label1.Text += temp + "<br>";
        }
    }
}