DataSourceCacheDurationConverter 类

定义

public ref class DataSourceCacheDurationConverter : System::ComponentModel::Int32Converter

public class DataSourceCacheDurationConverter : System.ComponentModel.Int32Converter

type DataSourceCacheDurationConverter = class
    inherit Int32Converter

Public Class DataSourceCacheDurationConverter
Inherits Int32Converter

继承

Object

TypeConverter

BaseNumberConverter

Int32Converter

DataSourceCacheDurationConverter

示例

下面的代码示例演示如何在支持使用 TypeConverterAttribute 属性进行缓存的数据源控件上修饰属性。 在此示例中，数据源控件支持缓存语义，并公开三个按其他 ASP.NET 数据源控件建模的属性：EnableCaching、CacheDuration 和 CacheExpirationPolicy。 该 CacheDuration 属性使用 DataSourceCacheDurationConverter 类型转换器。

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.");
    }
    
    // ...
}

<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

注解

ASP.NET 支持缓存的数据源控件通常提供一个 CacheDuration 属性，该属性可以设置为控件缓存数据的秒数。 值 0 表示这些缓存上下文中的“Infinite”，类 DataSourceCacheDurationConverter 负责此显式转换。

页面开发人员不使用该 DataSourceCacheDurationConverter 类。 控制开发支持缓存的数据源控件的开发人员，以及 TypeConverterAttribute 属性来修饰表示自定义数据源控件的缓存持续时间设置的属性。

另请参阅

• CacheDuration
• CacheDuration
• CacheDuration
• Int32Converter