SqlCacheDependency
web页面代码片段：
web页面代码
String connectionString
=
"
Data Source=localhost;Initial Catalog=BalloonShop;Integrated Security=True
"
;
DataTable dt = (DataTable)HttpContext.Current.Cache[ " Customer_test " ];
if (dt == null )
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
String sqlStr = " SELECT dbo.Product.ProductID, Name, col_name FROM " +
" dbo.Product inner join dbo.ProductCategory on " +
" dbo.Product.ProductID = dbo.ProductCategory.ProductID inner join " +
" dbo.tb_category on dbo.ProductCategory.CategoryID = dbo.tb_category.col_id " ;
conn.Open();
SqlCommand command = new SqlCommand();
command.Connection = conn;
command.CommandText = sqlStr;
// DataTableCache.Dependency = new SqlCacheDependency(command);
SqlCacheDependency dependency = new SqlCacheDependency(command)；
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataSet ds = new DataSet();
adapter.Fill(ds, " Customers " );
dt = ds.Tables[ 0 ];
// command.Connection.Close();
DataTableCache.AddCache( " Customer_test " , dt, command);//缓存通知失效 不起作用
DataTableCache.AddCache("Customer_test", dt, dependency );// 成功
// HttpContext.Current.Cache.Insert("Customer_test", dt, dependency);
}
}
gvwCustomers.DataSource = dt;
gvwCustomers.DataBind();
DataTable dt = (DataTable)HttpContext.Current.Cache[ " Customer_test " ];
if (dt == null )
{
using (SqlConnection conn = new SqlConnection(connectionString))
{
String sqlStr = " SELECT dbo.Product.ProductID, Name, col_name FROM " +
" dbo.Product inner join dbo.ProductCategory on " +
" dbo.Product.ProductID = dbo.ProductCategory.ProductID inner join " +
" dbo.tb_category on dbo.ProductCategory.CategoryID = dbo.tb_category.col_id " ;
conn.Open();
SqlCommand command = new SqlCommand();
command.Connection = conn;
command.CommandText = sqlStr;
// DataTableCache.Dependency = new SqlCacheDependency(command);
SqlCacheDependency dependency = new SqlCacheDependency(command)；
SqlDataAdapter adapter = new SqlDataAdapter(command);
DataSet ds = new DataSet();
adapter.Fill(ds, " Customers " );
dt = ds.Tables[ 0 ];
// command.Connection.Close();
DataTableCache.AddCache( " Customer_test " , dt, command);//缓存通知失效 不起作用
DataTableCache.AddCache("Customer_test", dt, dependency );// 成功
// HttpContext.Current.Cache.Insert("Customer_test", dt, dependency);
}
}
gvwCustomers.DataSource = dt;
gvwCustomers.DataBind();
DataTableCahche的代码片段：
DataTableCache代码
public
class
DataTableCache
{
private DataTableCache(){ }
private static SqlCacheDependency dependency = null ;
public static SqlCacheDependency Dependency {
get { return dependency; }
set { dependency = value; }
}
public static void AddCache(String key, DataTable dt,SqlCommand command) {
dependency = new SqlCacheDependency(command);
HttpContext.Current.Cache.Insert(key, dt, dependency);
}
public static void AddCache(String key, DataTable dt, SqlCacheDependency dependency) {
HttpContext.Current.Cache.Insert(key, dt, dependency);
}
public static void AddCache(String key, DataTable dt) {
HttpRuntime.Cache.Insert(key,dt, dependency);
}
}
当我使用上面红色的部分插入cache的时候，我改变数据库中的数据时，界面上的数据却不会变化，通知失效机制不能成功运行，
当我使用蓝色的部分插入cache的时候， 我改变数据库中的数据时，界面上的数据能发生变化，通知失效机制能成功运行，我很困惑，这到底是什么原因？
{
private DataTableCache(){ }
private static SqlCacheDependency dependency = null ;
public static SqlCacheDependency Dependency {
get { return dependency; }
set { dependency = value; }
}
public static void AddCache(String key, DataTable dt,SqlCommand command) {
dependency = new SqlCacheDependency(command);
HttpContext.Current.Cache.Insert(key, dt, dependency);
}
public static void AddCache(String key, DataTable dt, SqlCacheDependency dependency) {
HttpContext.Current.Cache.Insert(key, dt, dependency);
}
public static void AddCache(String key, DataTable dt) {
HttpRuntime.Cache.Insert(key,dt, dependency);
}
}
当我使用上面红色的部分插入cache的时候，我改变数据库中的数据时，界面上的数据却不会变化，通知失效机制不能成功运行，
当我使用蓝色的部分插入cache的时候， 我改变数据库中的数据时，界面上的数据能发生变化，通知失效机制能成功运行，我很困惑，这到底是什么原因？
提问于2010-01-19 11:57
所有回答(2)
