C# 缓存学习总结

 <!--连接数据库语句-->

<configuration>
  <connectionStrings>
    <add name="Config" connectionString="Data Source=.;Initial Catalog=CacheData;Persist Security Info=True;User ID=sa;Password=123" providerName="System.Data.SqlClient"/>
  </connectionStrings>

<!--在system.web节点下添加-->
<!--注意事项：配置中add name值为数据库名，connectionStringName为连接数据库字段的名称要相同-->

<caching>
      <sqlCacheDependency enabled="true" pollTime="1000">

        <databases>
          <add name="CacheData" connectionStringName="Config" pollTime="1000"/>
        </databases>
      </sqlCacheDependency>
      
    </caching>

 private static SqlCacheDependency MyDep;
        protected void Page_Load(object sender, EventArgs e)
        {
            Label1.Text = DateTime.Now.ToString();
            if (!IsPostBack)
            {
                //Cache为数据库名,T_SqlCache为缓存表
               
                DataSet ds = GetSet();
                if (Cache["SqlCon"] == null)
                {
                    //添加缓存SqlCon,缓存值为数据库表内容，
                    MyDep = new SqlCacheDependency("Cache", "T_SqlCache");
                    Cache.Add("SqlCon", ds, MyDep, DateTime.Now.AddSeconds(60), TimeSpan.Zero, CacheItemPriority.Normal, null);
                } 
               
            }
        }
         
        protected void Button1_Click(object sender, EventArgs e)
        {
            if (MyDep.HasChanged)
            {//当数据库值更改时提醒；
                Response.Write("数据库修改时间为："+MyDep.UtcLastModified);
            }
            if (Cache["SqlCon"] == null)
            {//当缓存过期或数据库值修改后缓存从新加载
                MyDep = new SqlCacheDependency("Ajax", "T_AjaxLD");
                DataSet ds = GetSet();
                Cache.Add("SqlCon", ds, MyDep, DateTime.Now.AddSeconds(60), TimeSpan.Zero, CacheItemPriority.Normal, null);
            }
            this.GridView1.DataSource = Cache["SqlCon"];//绑定数据
            this.GridView1.DataBind();
        }
        /// <summary>
        /// 生成Dataset
        /// </summary>
        /// <returns></returns>
        private DataSet GetSet()
        {
            DataSet ds = new DataSet();
            string sql = "select * from T_SqlCache";
            string Config = ConfigurationManager.ConnectionStrings["Config"].ConnectionString;//连接数据库语句
            using (SqlConnection cnn = new SqlConnection(Config))
            {
                using (SqlCommand cmm = new SqlCommand(sql, cnn))
                {
                    SqlDataAdapter dapter = new SqlDataAdapter(cmm);
                    dapter.Fill(ds);
                }
            }

            return ds;
        }