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.

Inheritance Hierarchy

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

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

Visual Basic
Public Class DataSourceCacheDurationConverter _
	Inherits Int32Converter
C#
public class DataSourceCacheDurationConverter : Int32Converter
Visual C++
public ref class DataSourceCacheDurationConverter : public Int32Converter
F#
type DataSourceCacheDurationConverter =  
    class
        inherit Int32Converter
    end

The DataSourceCacheDurationConverter type exposes the following members.

Constructors

  Name Description
Public method DataSourceCacheDurationConverter Initializes a new instance of the DataSourceCacheDurationConverter class.
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Methods

  Name Description
Public method CanConvertFrom(Type) Returns whether this converter can convert an object of the given type to the type of this converter. (Inherited from TypeConverter.)
Public method CanConvertFrom(ITypeDescriptorContext, Type) Determines whether the DataSourceCacheDurationConverter can convert an object in the given source type to an Int32 object. (Overrides BaseNumberConverter.CanConvertFrom(ITypeDescriptorContext, Type).)
Public method CanConvertTo(Type) Returns whether this converter can convert the object to the specified type. (Inherited from TypeConverter.)
Public method CanConvertTo(ITypeDescriptorContext, Type) Returns a value indicating whether the DataSourceCacheDurationConverter instance can convert an object to the given destination type. (Overrides BaseNumberConverter.CanConvertTo(ITypeDescriptorContext, Type).)
Public method ConvertFrom(Object) Converts the given value to the type of this converter. (Inherited from TypeConverter.)
Public method ConvertFrom(ITypeDescriptorContext, CultureInfo, Object) Converts the specified object to an Int32 object. (Overrides BaseNumberConverter.ConvertFrom(ITypeDescriptorContext, CultureInfo, Object).)
Public method ConvertFromInvariantString(String) Converts the given string to the type of this converter, using the invariant culture. (Inherited from TypeConverter.)
Public method ConvertFromInvariantString(ITypeDescriptorContext, String) Converts the given string to the type of this converter, using the invariant culture and the specified context. (Inherited from TypeConverter.)
Public method ConvertFromString(String) Converts the specified text to an object. (Inherited from TypeConverter.)
Public method ConvertFromString(ITypeDescriptorContext, String) Converts the given text to an object, using the specified context. (Inherited from TypeConverter.)
Public method ConvertFromString(ITypeDescriptorContext, CultureInfo, String) Converts the given text to an object, using the specified context and culture information. (Inherited from TypeConverter.)
Public method ConvertTo(Object, Type) Converts the given value object to the specified type, using the arguments. (Inherited from TypeConverter.)
Public method ConvertTo(ITypeDescriptorContext, CultureInfo, Object, Type) Converts the specified object to another type. (Overrides BaseNumberConverter.ConvertTo(ITypeDescriptorContext, CultureInfo, Object, Type).)
Public method ConvertToInvariantString(Object) Converts the specified value to a culture-invariant string representation. (Inherited from TypeConverter.)
Public method ConvertToInvariantString(ITypeDescriptorContext, Object) Converts the specified value to a culture-invariant string representation, using the specified context. (Inherited from TypeConverter.)
Public method ConvertToString(Object) Converts the specified value to a string representation. (Inherited from TypeConverter.)
Public method ConvertToString(ITypeDescriptorContext, Object) Converts the given value to a string representation, using the given context. (Inherited from TypeConverter.)
Public method ConvertToString(ITypeDescriptorContext, CultureInfo, Object) Converts the given value to a string representation, using the specified context and culture information. (Inherited from TypeConverter.)
Public method CreateInstance(IDictionary) Re-creates an Object given a set of property values for the object. (Inherited from TypeConverter.)
Public method CreateInstance(ITypeDescriptorContext, IDictionary) Creates an instance of the type that this TypeConverter is associated with, using the specified context, given a set of property values for the object. (Inherited from TypeConverter.)
Public method Equals(Object) Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected method Finalize Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Protected method GetConvertFromException Returns an exception to throw when a conversion cannot be performed. (Inherited from TypeConverter.)
Protected method GetConvertToException Returns an exception to throw when a conversion cannot be performed. (Inherited from TypeConverter.)
Public method GetCreateInstanceSupported() Returns whether changing a value on this object requires a call to the CreateInstance method to create a new value. (Inherited from TypeConverter.)
Public method GetCreateInstanceSupported(ITypeDescriptorContext) Returns whether changing a value on this object requires a call to CreateInstance to create a new value, using the specified context. (Inherited from TypeConverter.)
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetProperties(Object) Returns a collection of properties for the type of array specified by the value parameter. (Inherited from TypeConverter.)
Public method GetProperties(ITypeDescriptorContext, Object) Returns a collection of properties for the type of array specified by the value parameter, using the specified context. (Inherited from TypeConverter.)
Public method GetProperties(ITypeDescriptorContext, Object, Attribute[]) Returns a collection of properties for the type of array specified by the value parameter, using the specified context and attributes. (Inherited from TypeConverter.)
Public method GetPropertiesSupported() Returns whether this object supports properties. (Inherited from TypeConverter.)
Public method GetPropertiesSupported(ITypeDescriptorContext) Returns whether this object supports properties, using the specified context. (Inherited from TypeConverter.)
Public method GetStandardValues() Returns a collection of standard values from the default context for the data type this type converter is designed for. (Inherited from TypeConverter.)
Public method GetStandardValues(ITypeDescriptorContext) Returns a collection of standard values for the data type the DataSourceCacheDurationConverter instance is designed for. (Overrides TypeConverter.GetStandardValues(ITypeDescriptorContext).)
Public method GetStandardValuesExclusive() Returns whether the collection of standard values returned from GetStandardValues is an exclusive list. (Inherited from TypeConverter.)
Public method GetStandardValuesExclusive(ITypeDescriptorContext) Specifies whether the collection of standard values returned from the GetStandardValues method is an exclusive list, using the specified context. (Overrides TypeConverter.GetStandardValuesExclusive(ITypeDescriptorContext).)
Public method GetStandardValuesSupported() Returns whether this object supports a standard set of values that can be picked from a list. (Inherited from TypeConverter.)
Public method GetStandardValuesSupported(ITypeDescriptorContext) Specifies whether the DataSourceCacheDurationConverter object supports a standard set of values that can be picked from a list, using the specified context. (Overrides TypeConverter.GetStandardValuesSupported(ITypeDescriptorContext).)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Public method IsValid(Object) Returns whether the given value object is valid for this type. (Inherited from TypeConverter.)
Public method IsValid(ITypeDescriptorContext, Object) Returns whether the given value object is valid for this type and for the specified context. (Inherited from TypeConverter.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method SortProperties Sorts a collection of properties. (Inherited from TypeConverter.)
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
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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.");
    }

    // ...
}


Version Information

.NET Framework

Supported in: 4, 3.5, 3.0, 2.0
Platforms

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows XP SP2 x64 Edition, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.
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.
See Also

Reference