LINQ竖表转横表

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

namespace TISCOMQTT.components
{
    internal class V2H
    {
        public static DataTable ConvertDataTable(DataTable source)
        {
            try
            {
                
                DataTable dt=new DataTable();
                dt.Columns.Add("COIL_NUMBER_IN");
                dt.Columns.Add("WORK_TIME");
                dt.Columns.Add("DEAL_FLAG");
                dt.Columns.Add("PROD_UNIT_CODE");
                dt.Columns.Add("PROD_UNIT_SEG");
                var columns=(from x in source.Rows.Cast<DataRow>() select x[6].ToString()).Distinct();

                foreach(var item in columns)
                {
                    dt.Columns.Add(item);
                }
                var data = from x in source.Rows.Cast<DataRow>()
                           group x by new
                           {
                               subID=x[0],
                               mainID=x[1]
                           }
                           into g
                           select new { key1 = g.Key.subID.ToString(), key2=g.Key.mainID.ToString(),Items = g };
                data.ToList().ForEach(x =>
                {
                    String[] array = new string[dt.Columns.Count];
                    array[0] = x.key1;
                    array[1] = x.key2;
                    for (int i = 2; i < dt.Columns.Count; i++)
                    {
                        array[i] = (from y in x.Items
                                    where y[2].ToString() == dt.Columns[i].ToString()
                                    select y[4].ToString()+" "+y[5].ToString()
                                    ).SingleOrDefault();
                    }
                    dt.Rows.Add(array);
                });

                return dt;
            }catch(Exception ex)
            {
                MessageBox.Show("竖表转横表错误："+ex.Message.ToString(),"系统提示",MessageBoxButtons.OK,MessageBoxIcon.Error);
                return null;
            }
        }
    }
}