在Gridview如何进行每行单元格比较

有在论坛上看到一个问题，就是在Gridview控件中，需要对几个列的数值进行比较，原问题如下：

先在数据库中准备数据：

CREATE TABLE [dbo].[RecordTime]
(
    Id INT IDENTITY(1,1) PRIMARY KEY,
    Time1 DATETIME,
    Time2 DATETIME,
    Time3 DATETIME,
    Time4 DATETIME
)
GO
INSERT INTO [dbo].[RecordTime] VALUES ('2015-05-11 09:48','2015-05-20 10:08','2015-05-13 14:48','2015-05-19 08:48'),
                                      ('2015-05-10 14:48','2015-05-01 10:02','2015-05-20 12:48','2015-05-20 10:20'),
                                      ('2015-05-20 10:31','2015-05-03 10:40','2015-05-14 10:40','2015-05-25 09:48')
  GO

 CREATE PROCEDURE [dbo].[usp_RecordTime_GetAll]
 AS
    SELECT [Id],[Time1],[Time2],[Time3],[Time4] FROM [dbo].[RecordTime]
GO

在aspx网页上写好GridView控件：

然后可以在.aspx.cs代码页中实现OnRowDataBound="GridView1_RowDataBound"事件：

.aspx.cs代码：

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using Insus.NET;
using System.Data;
using System.Drawing;

public partial class _Default : System.Web.UI.Page
{
    RecordTime rt = new RecordTime();
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
            Data_Binding();
    }

    private void Data_Binding()
    {
        this.GridView1.DataSource = rt.GetRecordTime();
        this.GridView1.DataBind();
    }

    protected void GridView1_RowDataBound(object sender, GridViewRowEventArgs e)
    {
        if (e.Row.RowType != DataControlRowType.DataRow) return;

        DataRowView drv = (DataRowView)e.Row.DataItem;
        List<DateTime> lDT = new List<DateTime>();
        lDT.Add(Convert.ToDateTime(drv["Time1"]));
        lDT.Add(Convert.ToDateTime(drv["Time2"]));
        lDT.Add(Convert.ToDateTime(drv["Time3"]));
        lDT.Add(Convert.ToDateTime(drv["Time4"]));
        DateTime dt = lDT.Max<DateTime>();
        int i = lDT.IndexOf(dt);

        int actualIdx = i + ;

        e.Row.Cells[actualIdx].ForeColor = Color.FromName("red");
    }
}

运行得到的效果：