ImportAttribute Class
Specifies that a property, field, or parameter value should be provided by the CompositionContainer.
Assembly: System.ComponentModel.Composition (in System.ComponentModel.Composition.dll)
The ImportAttribute type exposes the following members.
| Name | Description | |
|---|---|---|
![]() ![]() | ImportAttribute() | Initializes a new instance of the ImportAttribute class, importing the export with the default contract name. |
![]() ![]() | ImportAttribute(String) | Initializes a new instance of the ImportAttribute class, importing the export with the specified contract name. |
![]() ![]() | ImportAttribute(Type) | Initializes a new instance of the ImportAttribute class, importing the export with the contract name derived from the specified type. |
![]() ![]() | ImportAttribute(String, Type) | Initializes a new instance of the ImportAttribute class, importing the export with the specified contract name and type. |
| Name | Description | |
|---|---|---|
![]() ![]() | AllowDefault | Gets or sets a value that indicates whether the property, field, or parameter will be set to its type's default value when an export with the contract name is not present in the container. |
![]() ![]() | AllowRecomposition | Gets or sets a value that indicates whether the property or field will be recomposed when exports with a matching contract have changed in the container. |
![]() ![]() | ContractName | Gets the contract name of the export to import. |
![]() ![]() | ContractType | Gets the type of the export to import. |
![]() ![]() | RequiredCreationPolicy | Gets or sets a value that indicates that the importer requires a specific CreationPolicy for the exports used to satisfy this import. |
![]() | TypeId | When implemented in a derived class, gets a unique identifier for this Attribute. (Inherited from Attribute.) |
| Name | Description | |
|---|---|---|
![]() ![]() | 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.) |
| Name | Description | |
|---|---|---|
![]() ![]() | _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.) |
In the Attributed Programming Model, the ImportAttribute is used to declare the imports, or dependencies, of a given part. It can decorate a property, a field, or a method. During composition, a part's imports will be filled by the CompositionContainer object to which that part belongs, by using the exports provided to that CompositionContainer object.
Whether an import matches a given export is determined primarily by comparing the contract name and the contract type. Ordinarily, you do not have to specify either of these when using the import attribute in code, and they will be automatically inferred from the type of the decorated member. If the import must match an export of a different type (for example, a subclass of the type of the decorated member, or an interface implemented by that member), then the contract type must be explicitly specified. The contract name can also be explicitly specified, for example to distinguish between multiple contracts with the same type, but it is usually better to do this through metadata. For more information about metadata, see PartMetadataAttribute.
Windows 7, Windows Vista SP1 or later, Windows XP SP3, 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.

