lambda表达式操作DataTable

using System;
using System.Collections.Generic;
using System.Data;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace ConsoleApp1
{
class Program
{
static void Main(string[] args)
{
DataTable dtNew = new DataTable();
dtNew.Columns.Add("Index", Type.GetType("System.String"));
dtNew.Columns.Add("Name", Type.GetType("System.String"));
dtNew.Columns.Add("Age", Type.GetType("System.String"));
dtNew.Columns.Add("Class", Type.GetType("System.String"));
for (int i = 0; i < 3; i++)
{
DataRow dr = dtNew.NewRow();
dr["Index"] = i;
dr["Name"] = "张三";
dr["Age"] = i+1;
dr["Class"] = i+2;
dtNew.Rows.Add(dr);
}

DataTable table = dtNew.Copy();
Dictionary<string, DataTable> dt = table.AsEnumerable().GroupBy(x => x["Index"].ToString()).ToDictionary(x => x.Key,
y =>
{
DataTable tb = table.Clone();
foreach (var item in y)
{
DataRow row = tb.NewRow();
for (int i = 0; i < item.ItemArray.Count(); i++)
{
row[i] = item[i];
}
tb.Rows.Add(row);
}
return tb;
});
}
}
}