Declaratively instructs the .NET Framework to instantiate a configuration property. This class cannot be inherited.
Assembly: System.Configuration (in System.Configuration.dll)
Thetype exposes the following members.
|DefaultValue||Gets or sets the default value for the decorated property.|
|IsDefaultCollection||Gets or sets a value indicating whether this is the default property collection for the decorated configuration property.|
|IsKey||Gets or sets a value indicating whether this is a key property for the decorated element property.|
|IsRequired||Gets or sets a value indicating whether the decorated element property is required.|
|Name||Gets the name of the decorated configuration-element property.|
|Options||Gets or sets the ConfigurationPropertyOptions for the decorated configuration-element property.|
|TypeId||When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.)|
|Equals||Infrastructure. Returns a value that indicates whether this instance is equal to a specified object. (Inherited from Attribute.)|
|Finalize||Allows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)|
|GetHashCode||Returns the hash code for this instance. (Inherited from Attribute.)|
|GetType||Gets the Type of the current instance. (Inherited from Object.)|
|IsDefaultAttribute||When overridden in a derived class, indicates whether the value of this instance is the default value for the derived class. (Inherited from Attribute.)|
|Match||When overridden in a derived class, returns a value that indicates whether this instance equals a specified object. (Inherited from Attribute.)|
|MemberwiseClone||Creates a shallow copy of the current Object. (Inherited from Object.)|
|ToString||Returns a string that represents the current object. (Inherited from Object.)|
|_Attribute.GetIDsOfNames||Maps a set of names to a corresponding set of dispatch identifiers. (Inherited from Attribute.)|
|_Attribute.GetTypeInfo||Retrieves the type information for an object, which can be used to get the type information for an interface. (Inherited from Attribute.)|
|_Attribute.GetTypeInfoCount||Retrieves the number of type information interfaces that an object provides (either 0 or 1). (Inherited from Attribute.)|
|_Attribute.Invoke||Provides access to properties and methods exposed by an object. (Inherited from Attribute.)|
You use the to decorate a configuration property, which will instruct the .NET Framework to instantiate and to initialize the property using the value of the decorating parameter.
The simplest way to create a custom configuration element is to use the attributed (declarative) model. You declare the custom public properties and decorate them with the attribute. For each property marked with this attribute, the .NET Framework uses reflection to read the decorating parameters and create a related ConfigurationProperty instance. You can also use the programmatic model, in which case it is your responsibility to declare the custom public properties and return their collection.
The .NET Framework configuration system provides attribute types that you can use during the creation of custom configuration elements. There are two kinds of attribute types:
The types instructing the .NET Framework how to instantiate the custom configuration-element properties. These types include:
The types instructing the .NET Framework how to validate the custom configuration-element properties. These types include:
The following example shows how to define the properties of a custom ConfigurationSection object using the attribute.
The example contains two classes. The UrlsSection custom class uses the to define its own properties. The UsingConfigurationPropertyAttribute class uses the UrlsSection to read and write the custom section in the application configuration file.
The following is an excerpt of the configuration file containing the custom section as defined in the previous sample.
<?xml version="1.0" encoding="utf-8"?> <configuration> <configSections> <section name="CustomSection" type="UrlsSection, UsingConfigurationPropertyAttribute, Version=188.8.131.52, Culture=neutral, PublicKeyToken=null" /> </configSections> <CustomSection name="Contoso" url="http://www.contoso.com" /> </configuration>
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.