GridView 行交换 GridView 行上移下移

using System;
using System.Configuration;
using System.Data;
//using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
//using System.Xml.Linq;
 
public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
        if (!IsPostBack)
        {
            DataTable dt = CreateDataTable();
 
            GridView1.DataSource = dt;
            GridView1.DataBind();
        }
 
    }
    /// <summary>
    /// 
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public DataTable CreateDataTable()
    {
        DataTable dt = new DataTable();
        
        //DataColumn dc=dt.n
        dt.Columns.Add("id", typeof(Int16));
        dt.Columns.Add("name", typeof(String));
        dt.Columns.Add("age", typeof(Int16));
        for (int i = 0; i < 6; i++)
        {
            DataRow dr = dt.NewRow();
            dr["id"] = i;
            dr["name"] = "aa"+i.ToString();;
            dr["age"] = 12+i;
            
            dt.Rows.Add(dr);
        }
        ViewState["dataTable"] = dt;
        return dt;
    }
    protected void exchangeRow(DataRow dataRow, DataRow tempRow)
    {
        tempRow["id"] = dataRow["id"];
        tempRow["name"] = dataRow["name"];
        tempRow["age"] = dataRow["age"];
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        DataTable dataTable = (DataTable)ViewState["dataTable"];
        string rowindex=((GridViewRow)((Button)sender).Parent.Parent).RowIndex.ToString();
 
        if (int.Parse(rowindex) - 1 < 0)
        {
            Page.RegisterStartupScript("", "<script>alert('TOP!');</script>");
        }
        else
        {
            DataRow tempRow = dataTable.NewRow();
            exchangeRow(dataTable.Rows[int.Parse(rowindex) - 1], tempRow);
            exchangeRow(dataTable.Rows[int.Parse(rowindex)], dataTable.Rows[int.Parse(rowindex) - 1]);
            exchangeRow(tempRow, dataTable.Rows[int.Parse(rowindex)]);            
        }
        GridView1.DataSource = dataTable;
        GridView1.DataBind();
    }
    protected void Button2_Click(object sender, EventArgs e)
    {
        DataTable dataTable = (DataTable)ViewState["dataTable"];
        string rowindex = ((GridViewRow)((Button)sender).Parent.Parent).RowIndex.ToString();      
        if (int.Parse(rowindex) + 1 > dataTable.Rows.Count - 1)
        {
            Page.RegisterStartupScript("", "<script>alert('END!');</script>");
        }
        else
        {
 
            DataRow tempRow = dataTable.NewRow();
            exchangeRow(dataTable.Rows[int.Parse(rowindex) + 1], tempRow);
            exchangeRow(dataTable.Rows[int.Parse(rowindex)], dataTable.Rows[int.Parse(rowindex) + 1]);
            exchangeRow(tempRow, dataTable.Rows[int.Parse(rowindex)]);
        }
        GridView1.DataSource = dataTable;
        GridView1.DataBind();
    }
}