設定緩衝的位置---屬性Location(取來自OutputCacheLocation枚舉類型的一個值)：Any---預設值。頁面可在任何地方緩衝，包括伺服器、下遊伺服器、瀏覽器。Client---頁面的輸出只在瀏覽器緩衝。DownStream----頁面的輸出只在下遊伺服器上緩衝。None----不執行頁面快取作業。Server----頁面只在伺服器端緩衝。使用HttpCachePolicy類--精確控制頁面的緩衝行為其中SetExpires()方法表示頁面到期的日期，SetCacheability()方法表示頁面要如何來緩衝。SetCachability()方法取HttpCacheability枚舉類型中的值：NoCache---防止任何頁面用Cache-Control:no-cache頭來緩衝。Private--表示頁面不應當被Proxy 伺服器來緩衝，但可以被瀏覽器緩衝。預設值。Public--表示頁面可以被瀏覽器和Proxy 伺服器緩衝。Server--表示頁面只可以在伺服器端被緩衝。三：使用頁面片段快取頁面片段快取是通過使用者服務控制項來實現的。通過為頁面的每個地區建立一個單獨的使用者控制項，就可以定義頁面的不同地區。在每個使用者控制項中，可以使用OutputCache指令來表示如何緩衝控制項的輸出。注意：在預設情況下，每個使用者控制項的輸出都被單獨緩衝起來，如果要跨多個使用者控制項共用同樣的輸出緩衝，以節省內在開銷，那麼可以使用Shared屬性<%@ OutputCache Duration="60" VaryByParam="*" Shared="true" %>頁面片段快取的限制：由於控制項被緩衝了，就不能在頁面中編程設定使用者控制項的屬性；也不能對被緩衝的使用者控制項使用資料繫結的文法。四：使用頁面資料緩衝每個ASP.NET應用程式都有一個Cache對象，直到應用程式重新啟動之前該對象一直可用。 Cache.Insert("t1", "goodtyl");//新增項
Cache.Insert("t2", "weiwei");
Cache.Insert("t3", "haha");
Cache.Remove("t3");//移除項
//遍曆Cache,注意System.Collections.DictionaryEntry:定義可設定或可檢索的字典鍵/值對
foreach(DictionaryEntry temp in Cache)
{
Response.Write("key: " + temp.Key.ToString() + "value: " + temp.Value.ToString() + "<br>");
}
添加快取檔案依賴：在添加一個檔案依賴時，可以把該項與一個檔案相關聯。如果檔案發生改變，就自動從緩衝中刪除該項。如例：Cache.Insert("mi","hello",new System.Web.Caching.CacheDependency(MapPath("a.txt")));如果a.txt被修改了，那麼,mi就自動從緩衝中刪除。添加緩衝觸發依賴：只要資料庫表的記錄發生改變就更新緩衝中的一項。需要使用sqlserver觸發器及xp_cmdshell擴充預存程序。CREATE TRIGGER UpdateCache
ON Products
FOR UPDATE, DELETE, INSERT
AS
DECLARE @cmd Varchar( 200 )
SELECT @cmd = 'echo ' + Cast( getDATE() As Varchar( 50 ) ) +
' > c:\tableChange.txt'
EXEC master..xp_cmdshell @cmd, no_output代碼：<%@ Page Language="C#" %>
<%@ Import Namespace="System.Data" %>
<%@ Import Namespace="System.Data.SqlClient" %><script language="C#" runat="server">void Page_Load(Object sender , EventArgs e)
{
DataSet dstProducts = (DataSet)(Cache[ "productsDS" ]);
if ( dstProducts == null )
{
dstProducts = GetProducts();
Cache.Insert( "Products", dstProducts, new CacheDependency( "c:\\tableChange.txt" ) );
}
dgrdProducts.DataSource = dstProducts;
dgrdProducts.DataBind();
}DataSet GetProducts() {
SqlConnection conNorthwind;
string strSelect;
SqlDataAdapter dadProducts;
DataSet dstProducts;conNorthwind = new SqlConnection( @"Server=localhost;Integrated Security=SSPI;Database=Northwind" );
strSelect = "Select TOP 20 * From Products ORDER BY ProductID";
dadProducts = new SqlDataAdapter( strSelect, conNorthwind );
dstProducts = new DataSet();
dadProducts.Fill( dstProducts, "ProductsDS" );
return dstProducts;
}</script><html>
<head><title>DatabaseDependency.aspx</title>
</head>
<body><asp:DataGrid
ID="dgrdProducts"
Runat="Server" /></body>
</html>
添加緩衝鍵依賴：<%@ Page Language="C#" %>
<script language="C#" runat="server">void UpdateItem1( object s, EventArgs e )
{
Cache[ "item1" ] = txtNewValue.Text;
}void UpdateItem2( object s, EventArgs e )
{
string arrKeyDepends = ( "item1" );
Cache.Insert( "item2", txtNewValue.Text, new CacheDependency( Server.MapPath(arrKeyDepends), System.DateTime.Now ) );
}</script><html>
<head><title>KeyDependency.aspx</title></head>
<body>
<form Runat="Server"><asp:TextBox
ID="txtNewValue"
Runat="Server" />
<p>
<asp:Button
Text="Update Item1"
OnClick="UpdateItem1"
Runat="Server" />
<asp:Button
Text="Update Item2"
OnClick="UpdateItem2"
Runat="Server" /><hr>Item1 = <%=Cache[ "item1" ]%>
<br>
Item2 = <%=Cache[ "item2" ]%></form>
</body>
</html>
建立一個絕對到期策略：Cache.Insert("Time", strTime, null, DateTime.Now.AddMinutes( 1 ), Cache.NoSlidingExpiration );建立相對到期策略：Cache.Insert("Time", strTime, null, Cache.NoAbsoluteExpiration, TimeSpan.FromMinutes( 1 ) );設定快取項目的優先順序：Cache.Insert("my","hello",null,Cache.NoAbsoluteExpiration,Cache.NoSlidingExpiration,CacheItemPriority.High,null);建立緩衝回調方法：在插入一個項到緩衝時，可以把一個回調方法與這個項關聯起來。無論是何種原因，只要該項從緩衝中刪除，那麼回調方法就自動執行。最明顯的回調應用是當一個項到期時自動把該項重新載入到緩衝中。範例程式碼：<%@ Page Language="C#" %>
<script language="C#" runat="server">public static CacheItemRemovedCallback onRemove;
//CacheItemRemovedReason表示從緩衝中刪除項的原因
void ItemRemoved( string strItemKey, object objItemValue, CacheItemRemovedReason objRemovedReason )
{
string strLogEntry;strLogEntry = "Item with value " + objItemValue.ToString() ;
strLogEntry = " removed at " + System.DateTime.Now.ToString( "T" );
strLogEntry = " because of " + objRemovedReason.ToString();
if ( Application[ "CacheLog" ] == null )
{
Application[ "CacheLog" ] = new ArrayList();
}
//Application[ "CacheLog" ].Add( "strLogEntry" );
//Beep();
}void btnAddCache_Click( object s, EventArgs e )
{
onRemove = new CacheItemRemovedCallback( ItemRemoved );
Cache.Insert( "myItem", txtNewValue.Text, null, DateTime.Now.AddSeconds( 10 ), Cache.NoSlidingExpiration, CacheItemPriority.High, onRemove );
}void btnRemoveCache_Click( object s, EventArgs e )
{
Cache.Remove( "myItem" );
}void Page_PreRender( object s, EventArgs e )
{
dgrdCacheLog.DataSource = Application[ "CacheLog" ];
dgrdCacheLog.DataBind();
}
</script><html>
<head><title>CacheCallback.aspx</title></head>
<body>
<form Runat="Server"><h2>Cache Log</h2>
<asp:DataGrid
ID="dgrdCacheLog"
CellPadding="8"
Runat="Server" />
<p>
<asp:TextBox
id="txtNewValue"
Runat="Server" />
<p>
<asp:Button
id="btnAddCache"
Text="Add To Cache!"
OnClick="btnAddCache_Click"
Runat="Server" /><asp:Button
id="btnRemoveCache"
Text="Remove From Cache!"
OnClick="btnRemoveCache_Click"
Runat="Server" /><asp:Button
Text="Refresh Page!"
Runat="Server" /></form>
</body>
</html>
註：本文轉自http://www.cnblogs.com/cgdaini/archive/2009/08/27/1554764.html
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