缓存DataSet

using System;  
using System.Data;  
using System.Configuration;  
using System.Collections;  
using System.Web;  
using System.Web.Security;  
using System.Web.UI;  
using System.Web.UI.WebControls;  
using System.Web.UI.WebControls.WebParts;  
using System.Web.UI.HtmlControls;  
using System.Data.SqlClient;  
 
   public partial class _Default : System.Web.UI.Page  
    {  
        protected void Page_Load(object sender, EventArgs e)  
        {  
            Response.Redirect("~/Login.aspx");  
            //构建新的dataset，并用Cache.Get()方法的结果为它赋值，          
            //该方法返回匹配指定键名的Object实列.所以要阄它转化为dataset类型          
            DataSet dst = (DataSet)Cache.Get("CachedDataSet");         
            //如果dst中没有内容即为空          
            if (dst == null)          
            {             
                //重新填充dst  并设置在内存中的保存时间...              
                this.Label1.Text = "The data came from a connction to the database";              
                SqlConnection con = new SqlConnection(ConfigurationManager.AppSettings["myCon"]);              
                con.Open();              
                SqlCommand cmd = new SqlCommand("select * from Test", con);              
                SqlDataAdapter dap = new SqlDataAdapter(cmd);              
                dst = new DataSet();              
                dap.Fill(dst, "Test");              
                //得到现在系统时间             
                dst.ExtendedProperties.Add("CreateTime", DateTime.Now.ToLongTimeString());              
                //设置在内存中的保存时间              
                Cache.Insert("CachedDataSet", dst, null, DateTime.Now.AddMinutes(5), TimeSpan.Zero);         
            }          
            else          
            {             
                //dataset中已经有数据时             
                this.Label1.Text = "The Data come from the cahe,It was created at:" + dst.ExtendedProperties["CreateTime"].ToString() +"<br>The current Time is:"+DateTime.Now.ToLongTimeString();          
            }          
            this.GridView1.DataSource = dst.Tables[0].DefaultView;//不要忘记绑定数据,两句常在一起哟。。。          
            this.GridView1.DataBind();  
        }  
    }