Declaratively instructs the .NET Framework to create an instance of a configuration element collection. This class cannot be inherited.
Assembly: System.Configuration (in System.Configuration.dll)
Thetype exposes the following members.
|AddItemName||Gets or sets the name of the <add> configuration element.|
|ClearItemsName||Gets or sets the name for the <clear> configuration element.|
|CollectionType||Gets or sets the type of the attribute.|
|ItemType||Gets the type of the collection element.|
|RemoveItemName||Gets or sets the name for the <remove> configuration element.|
|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.)|
|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.)|
|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 attribute to decorate a ConfigurationElementCollection element. This instructs the .NET Framework to create an instance of the collection and to initialize it using your custom ConfigurationElement values.
The simplest way to create a custom configuration element is to use the attributed (declarative) model. You declare the elements and decorate them with the attribute. For each element marked with this attribute, the .NET Framework uses reflection to read the decorating parameters and create a related ConfigurationElementCollection instance. You can also use the programmatic model. In this case it is your responsibility to declare the custom public collection but also to override the ConfigurationElementCollection member and return the properties 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 attributes:
The attributes that instruct the .NET Framework how to create instances of the custom configuration element properties. These types include:
The attributes that instruct the .NET Framework how to validate the custom configuration element properties. These types include:
The following example shows how to use the .
This example consists of three classes: UrlsSection, UrlsCollection and UrlConfigElement.The UrlsSection class uses the to define a custom configuration section. This section contains a URL collection (defined by the UrlsCollection class) of URL elements (defined by the UrlConfigElement class). When you run the example, an instance of the UrlsSection class is created and the following configuration elements are generated in the application configuration file:
<configuration> <configSections> <section name="MyUrls" type="UrlsSection, ConfigurationCollectionAttribute, Version=18.104.22.168, Culture=neutral, PublicKeyToken=null" /> </configSections> <MyUrls> <urls> <remove name="Contoso" /> <add name="Contoso" url="http://www.contoso.com" port="0" /> </urls> </MyUrls> </configuration