PartialCachingAttribute Class

 

Defines the metadata attribute that Web Forms user controls (.ascx files) use to indicate if and how their output is cached. This class cannot be inherited.

Namespace:   System.Web.UI
Assembly:  System.Web (in System.Web.dll)

System.Object
  System.Attribute
    System.Web.UI.PartialCachingAttribute

[AttributeUsageAttribute(AttributeTargets.Class)]
public sealed class PartialCachingAttribute : Attribute

NameDescription
System_CAPS_pubmethodPartialCachingAttribute(Int32)

Initializes a new instance of the PartialCachingAttribute class with the specified duration assigned to the user control to be cached.

System_CAPS_pubmethodPartialCachingAttribute(Int32, String, String, String)

Initializes a new instance of the PartialCachingAttribute class, specifying the caching duration, any GET and POST values, control names, and custom output caching requirements used to vary the cache.

System_CAPS_pubmethodPartialCachingAttribute(Int32, String, String, String, Boolean)

Initializes a new instance of the PartialCachingAttribute class, specifying the caching duration, any GET and POST values, control names, custom output caching requirements used to vary the cache, and whether the user control output can be shared with multiple pages.

System_CAPS_pubmethodPartialCachingAttribute(Int32, String, String, String, String, Boolean)

Initializes a new instance of the PartialCachingAttribute class, specifying the caching duration, any GET and POST values, control names, custom output caching requirements used to vary the cache, the database dependencies, and whether the user control output can be shared with multiple pages.

NameDescription
System_CAPS_pubpropertyDuration

Gets the amount of time, in seconds, that cached items should remain in the output cache.

System_CAPS_pubpropertyProviderName

Gets or sets the name of the provider that is used to store the output-cached data for the associated control.

System_CAPS_pubpropertyShared

Gets a value indicating whether user control output can be shared with multiple pages.

System_CAPS_pubpropertySqlDependency

Gets a delimited string that identifies one or more database and table name pairs that the cached user control is dependent on.

System_CAPS_pubpropertyTypeId

When implemented in a derived class, gets a unique identifier for this Attribute.(Inherited from Attribute.)

System_CAPS_pubpropertyVaryByControls

Gets a list of user control properties that the output cache uses to vary the user control.

System_CAPS_pubpropertyVaryByCustom

Gets a list of custom strings that the output cache will use to vary the user control.

System_CAPS_pubpropertyVaryByParams

Gets a list of query string or form POST parameters that the output cache will use to vary the user control.

NameDescription
System_CAPS_pubmethodEquals(Object)

This API supports the product infrastructure and is not intended to be used directly from your code. Returns a value that indicates whether this instance is equal to a specified object.(Inherited from Attribute.)

System_CAPS_pubmethodGetHashCode()

Returns the hash code for this instance.(Inherited from Attribute.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodIsDefaultAttribute()

When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class.(Inherited from Attribute.)

System_CAPS_pubmethodMatch(Object)

When overridden in a derived class, returns a value that indicates whether this instance equals a specified object.(Inherited from Attribute.)

System_CAPS_pubmethodToString()

Returns a string that represents the current object.(Inherited from Object.)

NameDescription
System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetIDsOfNames(Guid, IntPtr, UInt32, UInt32, IntPtr)

Maps a set of names to a corresponding set of dispatch identifiers.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfo(UInt32, UInt32, IntPtr)

Retrieves the type information for an object, which can be used to get the type information for an interface.(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.GetTypeInfoCount(UInt32)

Retrieves the number of type information interfaces that an object provides (either 0 or 1).(Inherited from Attribute.)

System_CAPS_pubinterfaceSystem_CAPS_privmethod_Attribute.Invoke(UInt32, Guid, UInt32, Int16, IntPtr, IntPtr, IntPtr, IntPtr)

Provides access to properties and methods exposed by an object.(Inherited from Attribute.)

The PartialCachingAttribute attribute class marks user controls (.ascx files) that support fragment caching, and encapsulates the cache settings that ASP.NET uses when caching the control. Page and controls developers use the PartialCachingAttribute attribute to enable output caching for a user control in a code-behind file.

Using the PartialCachingAttribute is one of several ways you can enable output caching. The following list describes methods you can use to enable output caching.

  • Use the directive to enable output caching in declarative scenarios.

  • Use the PartialCachingAttribute to enable caching for a user control in a code-behind file.

  • Use the ControlCachePolicy class to programmatically specify cache settings in programmatic scenarios in which you are working with BasePartialCachingControl instances.

If a user control contains an directive or has a PartialCachingAttribute applied, the ASP.NET parser generates an instance of the PartialCachingControl class to wrap the user control.

For more information about ASP.NET caching, see ASP.NET Caching. For more information about using attributes, see Extending Metadata Using Attributes.

The following code example demonstrates using the PartialCachingAttribute. This example has three parts:

  • A partial class, ctlMine, that inherits from the UserControl base class and to which the PartialCachingAttribute attribute is applied.

  • A user control that is used with the ctlMine partial class.

  • A Web Forms page that hosts the user control.

The first part of the example demonstrates a partial class that inherits from the UserControl base class and to which the PartialCachingAttribute attribute is applied. In this example, the attribute specifies that the user control should be cached for 20 seconds.

// [filename partialcache.cs]
// Create a code-behind user control that is cached
// for 20 seconds using the PartialCachingAttribute class.
// This control uses a DataGrid server control to display
// XML data.
using System;
using System.IO;
using System.Data;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace Samples.AspNet.CS.Controls
{

    // Set the PartialCachingAttribute.Duration property to 20 seconds.
    [PartialCaching(20)]
    public partial class ctlMine : UserControl
    {

        protected void Page_Load(Object Src, EventArgs E)
        {
            DataSet ds = new DataSet();

            FileStream fs = new FileStream(Server.MapPath("schemadata.xml"), FileMode.Open, FileAccess.Read);
            StreamReader reader = new StreamReader(fs);
            ds.ReadXml(reader);
            fs.Close();

            DataView Source = new DataView(ds.Tables[0]);
            // Use the LiteralControl constructor to create a new
            // instance of the class.
            LiteralControl myLiteral = new LiteralControl();
            // Set the LiteralControl.Text property to an HTML
            // string and the TableName value of a data source.
            myLiteral.Text = "<h6><font face=verdana>Caching an XML Table: " + Source.Table.TableName + " </font></h6>";
            MyDataGrid.DataSource = Source;
            MyDataGrid.DataBind();

            TimeMsg.Text = DateTime.Now.ToString("G");

        }
    }
}

The second part of the example shows a user control that is used with the previous example to demonstrate user control caching.

<!-- The mark-up .ascx file that displays the output of
     the partialcache.cs user control code-behind file. -->
<%@ Control language="C#" inherits="Samples.AspNet.CS.Controls.ctlMine" CodeFile="partialcache.cs.ascx.cs" %>

  <ASP:DataGrid id="MyDataGrid" runat="server"
    Width="900"
    BackColor="#ccccff"
    BorderColor="black"
    ShowFooter="false"
    CellPadding="3"
    CellSpacing="0"
    Font-Names="Verdana"
    Font-Size="8pt"
    HeaderStyle-BackColor="#aaaadd"
    EnableViewState="false"
  />

  <br />

  <i>Control last generated on:</i> <asp:label id="TimeMsg" runat="server" />

The third part of the example demonstrates a Web Forms page that hosts the user control.

<!-- The WebForms page that contains the user control generated
     by partialcache.cs. -->
<%@ Register TagPrefix="Acme" TagName="Cache" Src="partialcache.cs.ascx" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN"
    "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<script language="C#" runat="server">

      void Page_Load(Object Src, EventArgs E ) {

          TimeMsg.Text = DateTime.Now.ToString("G");
      }

  </script>

<head runat="server">
    <title>ASP.NET Example</title>
</head>
<body>

  <form id="form1" runat="server">
    <Acme:Cache runat="server"/>
    <br />

    <i>Page last generated on:</i> <asp:label id="TimeMsg" runat="server" />

  </form>
</body>
</html>

.NET Framework
Available since 1.1

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.

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