利用SQL2005的缓存依赖

private void BindPageData()
    {
        DataTable dt = (DataTable)HttpRuntime.Cache["Category"];
        if (dt == null)
        {
            SqlConnection con = new SqlConnection(ConfigurationManager.ConnectionStrings["ConnectionString"].ConnectionString);
            SqlCommand comm = new SqlCommand("select CategoryId,Name,Descn from Category", con);
            SqlDataAdapter sda = new SqlDataAdapter(comm);
            DataSet ds = new DataSet();
            sda.Fill(ds);
            dt = ds.Tables[0];

            SqlCacheDependency dep = new SqlCacheDependency("MSPetShop4", "Category");
            AggregateCacheDependency aggCd = new AggregateCacheDependency();
            aggCd.Add(dep);
            HttpRuntime.Cache.Add("Category", dt, aggCd, System.DateTime.Now.AddHours(1), Cache.NoSlidingExpiration, CacheItemPriority.High, null);
        }
        GridView1.DataSource = dt;
        GridView1.DataBind();
    }

<connectionStrings>
        <add name="ConnectionString" connectionString="Data Source=192.168.2.55;Initial Catalog=MSPetShop4;Persist Security Info=True;User Id=sa;PassWord=sa" providerName="System.Data.SqlClient"/>
    </connectionStrings>

<caching>
            <sqlCacheDependency enabled="true" pollTime="500">
                <databases>
                    <add name="MSPetShop4" connectionStringName="ConnectionString" pollTime="10000"/>
                </databases>
            </sqlCacheDependency>
        </caching>

[1]当然注意引用 :

using System.Data.SqlClient;
using System.Web.Caching;

[2]

SqlCacheDependency dep = new SqlCacheDependency("MSPetShop4", "Category");
将库与表名建立数据缓存关系;

AggregateCacheDependency aggCd = new AggregateCacheDependency();

建立缓存依赖;

HttpRuntime.Cache.Add()函数中的参数有些地方需要注意:

缓存失效的时间.当然也可以永不失效(Cache.NoAbsoluteExpiration);

[3]

注意此处的Cache来自HttpRuntime类,而非PAGE

[4]

注意数据库连接字符串配置地方是在<connectionStrings>节点中;

pollTime是数据库轮询时间（以毫秒为单位）。 如果数据库数据更新频繁,些值不能太大;

暂时这第着;有空了写个像PetShop4中那样层次分明的缓存机制;