asp.net代码练习 work084 使用Cache的示例

webform1.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="work084.WebForm1" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<Meta http-equiv="Content-Type" content="text/html; charset=utf-8"/>
    <title>使用Cache的示例</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:TextBox ID="txtContent" runat="server" Columns="50" Rows="10" TextMode="MultiLine"></asp:TextBox>
        <asp:Button ID="Button1" runat="server" Text="显示文件内容" OnClick="Button1_Click" />
    </div>
    </form>
</body>
</html>

webfrom1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace work084
{
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }

        protected void Button1_Click(object sender, EventArgs e)
        {
            string content = Cache["Content"] as string;

            if (content == null)
            {
                string path = Server.MapPath("~/Content.txt");
                string text = System.IO.File.ReadAllText(path, System.Text.Encoding.UTF8);
                System.Web.Caching.CacheDependency dependency = new System.Web.Caching.CacheDependency(path);
                System.Web.Caching.CacheItemRemovedCallback callBack = new System.Web.Caching.CacheItemRemovedCallback(ItemRemovedCallBack);
                Cache.Add("Content", text, dependency, System.Web.Caching.Cache.NoAbsoluteExpiration, new TimeSpan(0,30,0), System.Web.Caching.CacheItemPriority.Default, callBack);
                txtContent.Text = text;
            }
            else
            {
                txtContent.Text = content;
            }
        }

        private void ItemRemovedCallBack(string key, object value, System.Web.Caching.CacheItemRemovedReason reason)
        {
            string path = Server.MapPath("~/Log.txt");
            string log = string.Format("键为{0}的缓存项于{1}被删除，原因是：{2}。\r\n",key,DateTime.Now.ToString("yyyy-MM-dd HH:mm:ss"),reason.ToString());
            System.IO.File.AppendAllText(path, log);
        }
    }
}

asp.net代码练习 work084 使用Cache的示例

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