DataSourceCacheDurationConverter Class

Reference

Definition

Namespace:: System.Web.UI

Assembly:: System.Web.dll

Important

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

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

public class DataSourceCacheDurationConverter : System.ComponentModel.Int32Converter

type DataSourceCacheDurationConverter = class
    inherit Int32Converter

Public Class DataSourceCacheDurationConverter
Inherits Int32Converter

Inheritance: Object

TypeConverter

BaseNumberConverter

Int32Converter
DataSourceCacheDurationConverter

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.

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

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.

Constructors

DataSourceCacheDurationConverter()

Initializes a new instance of the DataSourceCacheDurationConverter class.

Methods

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

Applies to

次の方法で共有