DataSourceCacheDurationConverter Class (System.Web.UI)

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.NET Framework Class Library
DataSourceCacheDurationConverter Class

Provides a type converter to convert 32-bit signed integer objects to and from data source control cache duration representations.

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

Visual Basic (Declaration)
<AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
<AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level := AspNetHostingPermissionLevel.Minimal)> _
Public Class DataSourceCacheDurationConverter _
	Inherits Int32Converter
Visual Basic (Usage)
Dim instance As DataSourceCacheDurationConverter
C#
[AspNetHostingPermissionAttribute(SecurityAction.LinkDemand, Level = AspNetHostingPermissionLevel.Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction.InheritanceDemand, Level = AspNetHostingPermissionLevel.Minimal)]
public class DataSourceCacheDurationConverter : Int32Converter
Visual C++
[AspNetHostingPermissionAttribute(SecurityAction::LinkDemand, Level = AspNetHostingPermissionLevel::Minimal)]
[AspNetHostingPermissionAttribute(SecurityAction::InheritanceDemand, Level = AspNetHostingPermissionLevel::Minimal)]
public ref class DataSourceCacheDurationConverter : public Int32Converter
JScript
public class DataSourceCacheDurationConverter extends Int32Converter
Remarks

ASP.NET data source controls that support caching typically provide a CacheDuration property that you can set to the number of seconds that the control caches data. The value 0 represents "Infinite" in these caching contexts, and the DataSourceCacheDurationConverter class takes care of this explicit conversion.

Page developers do not use the DataSourceCacheDurationConverter class. Control developers who are developing data source controls that support caching use this type converter along with the TypeConverterAttribute attribute to decorate a property that represents a cache duration setting of a custom data source control.

Examples

The following code example demonstrates how you can decorate a property on a data source control that supports caching with a TypeConverterAttribute attribute. In this example, the data source control supports caching semantics and exposes three properties modeled after other ASP.NET data source controls: EnableCaching, CacheDuration, and CacheExpirationPolicy. The CacheDuration property uses the DataSourceCacheDurationConverter type converter.

Visual Basic

<NonVisualControl()>  _
Public Class SomeDataSource
    Inherits DataSourceControl
    ' Implementation of a custom data source control.
    ' The SdsCache object is an imaginary cache object
    ' provided for this example. It has not actual 
    ' implementation.
    Private myCache As New SdsCache()

    Friend ReadOnly Property Cache() As SdsCache 
        Get
            Return myCache
        End Get
    End Property 

    <TypeConverterAttribute(GetType(DataSourceCacheDurationConverter))>  _
    Public ReadOnly Property CacheDuration() As Integer 
        Get
            Return Cache.Duration
        End Get
    End Property 

    Public Property CacheExpirationPolicy() As DataSourceCacheExpiry 
        Get
            Return Cache.Expiry
        End Get
        Set
            Cache.Expiry = value
        End Set
    End Property 

    Public Property EnableCaching() As Boolean 
        Get
            Return Cache.Enabled
        End Get
        Set
            Cache.Enabled = value
        End Set
    End Property 

    Protected Overrides Function GetView(ByVal viewName As String) As System.Web.UI.DataSourceView
        Throw New Exception("The method or operation is not implemented.")
    End Function

    ' Continue implementation of data source control.
    ' ...

End Class 'SomeDataSource 


C#
using System;
using System.ComponentModel;
using System.Web.UI;

[ NonVisualControl() ]
public class SomeDataSource : DataSourceControl
{
    // Implementation of a custom data source control.

    // The SdsCache object is an imaginary cache object
    // provided for this example. It has not actual 
    // implementation.
    private SdsCache m_sdsCache = new SdsCache();
    internal SdsCache Cache {
        get { return m_sdsCache; }
    }

    [TypeConverterAttribute(typeof(DataSourceCacheDurationConverter))]
    public int CacheDuration {
        get { return Cache.Duration; }
    }

    public DataSourceCacheExpiry CacheExpirationPolicy {
        get { return Cache.Expiry; }
        set { Cache.Expiry = value; }
    }

    public bool EnableCaching {
        get { return Cache.Enabled; }
        set { Cache.Enabled = value; }
    }

    protected override DataSourceView GetView(string viewName)
    {
        throw new Exception("The method or operation is not implemented.");
    }

    // ...
}


.NET Framework Security

Inheritance Hierarchy

System.Object
  System.ComponentModel.TypeConverter
    System.ComponentModel.BaseNumberConverter
      System.ComponentModel.Int32Converter
        System.Web.UI.DataSourceCacheDurationConverter
Thread Safety

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

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0
See Also

Reference