Asp.net中获取DataTable选择第一行某一列值

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using Insus.NET.Models;
namespace Insus.NET.Entities
{
 public class CustomerEntity
 {
  public DataTable Customers()
  {
   DataTable dt = new DataTable();
   dt.Columns.Add(new DataColumn("CustomerID", typeof(int)));
   dt.Columns.Add(new DataColumn("CustomerName", typeof(string)));
   dt.Columns.Add(new DataColumn("PID", typeof(string)));
   DataRow dr = dt.NewRow();
   dr["CustomerID"] = 9; dr["CustomerName"] = "张三"; dr["PID"] = "123456789012";
   dt.Rows.Add(dr);
   dr = dt.NewRow();
   dr["CustomerID"] = 10; dr["CustomerName"] = "李四"; dr["PID"] = "321245677812";
   dt.Rows.Add(dr);
   dr = dt.NewRow();
   dr["CustomerID"] = 30; dr["CustomerName"] = "吴广"; dr["PID"] = "213445678912";
   dt.Rows.Add(dr);
   dr = dt.NewRow();
   dr["CustomerID"] = 35; dr["CustomerName"] = "王维"; dr["PID"] = "334456789012";
   dt.Rows.Add(dr);
   dr = dt.NewRow();
   dr["CustomerID"] = 36; dr["CustomerName"] = "赵勇"; dr["PID"] = "213445678912";
   dt.Rows.Add(dr);
   return dt;
  }
 }
}