Share via


CompositionContainer Class

Microsoft Silverlight will reach end of support after October 2021. Learn more.

Manages composition of parts.

Inheritance Hierarchy

System.Object
  System.ComponentModel.Composition.Hosting.ExportProvider
    System.ComponentModel.Composition.Hosting.CompositionContainer

Namespace:  System.ComponentModel.Composition.Hosting
Assembly:  System.ComponentModel.Composition (in System.ComponentModel.Composition.dll)

Syntax

'Declaration
Public Class CompositionContainer _
    Inherits ExportProvider _
    Implements ICompositionService, IDisposable
public class CompositionContainer : ExportProvider, 
    ICompositionService, IDisposable

The CompositionContainer type exposes the following members.

Constructors

  Name Description
Public method CompositionContainer() Initializes a new instance of the CompositionContainer class.
Public method CompositionContainer(array<ExportProvider[]) Initializes a new instance of the CompositionContainer class with the specified export providers.
Public method CompositionContainer(ComposablePartCatalog, array<ExportProvider[]) Initializes a new instance of the CompositionContainer class with the specified catalog and export providers.
Public method CompositionContainer(ComposablePartCatalog, Boolean, array<ExportProvider[]) Initializes a new instance of the CompositionContainer class with the specified catalog, thread-safe mode, and export providers.

Top

Properties

  Name Description
Public property Catalog Gets the ComposablePartCatalog that provides the container access to Export objects.
Public property Providers Gets the export providers that provide the container access to additional ComposablePartCatalog objects.

Top

Methods

  Name Description
Public method Compose Executes composition on the container, including the changes in the specified CompositionBatch.
Public method Dispose() Releases all resources used by the current instance of the CompositionContainer class.
Protected method Dispose(Boolean) Releases the unmanaged resources used by the CompositionContainer and optionally releases the managed resources.
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 the Object is reclaimed by garbage collection. (Inherited from Object.)
Public method GetExport<T>() Returns the export with the contract name derived from the specified type parameter. If there is not exactly one matching export, an exception is thrown. (Inherited from ExportProvider.)
Public method GetExport<T>(String) Returns the export with the specified contract name. If there is not exactly one matching export, an exception is thrown. (Inherited from ExportProvider.)
Public method GetExportedValue<T>() Returns the exported object with the contract name derived from the specified type parameter. If there is not exactly one matching exported object, an exception is thrown. (Inherited from ExportProvider.)
Public method GetExportedValue<T>(String) Returns the exported object with the specified contract name. If there is not exactly one matching exported object, an exception is thrown. (Inherited from ExportProvider.)
Public method GetExportedValueOrDefault<T>() Gets the exported object with the contract name derived from the specified type parameter or the default value for the specified type, or throws an exception if there is more than one matching exported object. (Inherited from ExportProvider.)
Public method GetExportedValueOrDefault<T>(String) Gets the exported object with the specified contract name or the default value for the specified type, or throws an exception if there is more than one matching exported object. (Inherited from ExportProvider.)
Public method GetExportedValues<T>() Gets all the exported objects with the contract name derived from the specified type parameter. (Inherited from ExportProvider.)
Public method GetExportedValues<T>(String) Gets all the exported objects with the specified contract name. (Inherited from ExportProvider.)
Public method GetExports(ImportDefinition) Gets all exports that match the conditions of the specified import definition. (Inherited from ExportProvider.)
Public method GetExports(ImportDefinition, AtomicComposition) Gets all exports that match the conditions of the specified import definition and composition. (Inherited from ExportProvider.)
Public method GetExports(Type, Type, String) Gets all the exports with the specified contract name. (Inherited from ExportProvider.)
Public method GetExports<T>() Gets all the exports with the contract name derived from the specified type parameter. (Inherited from ExportProvider.)
Public method GetExports<T>(String) Gets all the exports with the specified contract name. (Inherited from ExportProvider.)
Protected method GetExportsCore Returns a collection of all exports that match the conditions in the specified ImportDefinition object. (Overrides ExportProvider.GetExportsCore(ImportDefinition, AtomicComposition).)
Public method GetHashCode Serves as a hash function for a particular type. (Inherited from Object.)
Public method GetType Gets the Type of the current instance. (Inherited from Object.)
Protected method MemberwiseClone Creates a shallow copy of the current Object. (Inherited from Object.)
Protected method OnExportsChanged Raises the ExportsChanged event. (Inherited from ExportProvider.)
Protected method OnExportsChanging Raises the ExportsChanging event. (Inherited from ExportProvider.)
Public method ReleaseExport(Export) Releases the specified Export object from the CompositionContainer.
Public method ReleaseExport<T>(Lazy<T>) Removes the specified export from composition and releases its resources if possible.
Public method ReleaseExports(IEnumerable<Export>) Releases a set of Export objects from the CompositionContainer.
Public method ReleaseExports<T>(IEnumerable<Lazy<T>>) Removes a collection of exports from composition and releases their resources if possible.
Public method ReleaseExports<T, TMetadataView>(IEnumerable<Lazy<T, TMetadataView>>) Removes a collection of exports from composition and releases their resources if possible.
Public method SatisfyImportsOnce Satisfies the imports of the specified ComposablePart object without registering it for recomposition.
Public method ToString Returns a string that represents the current object. (Inherited from Object.)
Public method TryGetExports Gets all the exports that match the conditions of the specified import. (Inherited from ExportProvider.)

Top

Events

  Name Description
Public event ExportsChanged Occurs when the exports in the ExportProvider change. (Inherited from ExportProvider.)
Public event ExportsChanging Occurs when the provided exports are changing. (Inherited from ExportProvider.)

Top

Extension Methods

  Name Description
Public Extension Method ComposeExportedValue<T>(T) Overloaded. Creates a part from the specified value and composes it in the specified composition container. (Defined by AttributedModelServices.)
Public Extension Method ComposeExportedValue<T>(String, T) Overloaded. Creates a part from the specified object under the specified contract name and composes it in the specified composition container. (Defined by AttributedModelServices.)
Public Extension Method ComposeParts Creates composable parts from an array of attributed objects and composes them in the specified composition container. (Defined by AttributedModelServices.)
Public Extension Method SatisfyImportsOnce Composes the specified part by using the specified composition service, with recomposition disabled. (Defined by AttributedModelServices.)

Top

Remarks

A CompositionContainer object serves two major purposes in an application. First, it keeps track of which parts are available for composition and what their dependencies are, and serves as the context for any given composition. Second, it provides the methods by which the application can initiate composition, get instances of composed parts, or fill the dependencies of a composable part.

Parts can be made available to the container either directly or through the Catalog property. All the parts discoverable in this ComposablePartCatalog are available to the container to fulfill imports, along with any parts added directly.

The Compose method allows instantiated parts to be added to an existing container. Assuming composition is successful, these parts will have their imports filled with parts retrieved from the container, and their exports will be available to other parts. Imports marked as recomposable will be registered for recomposition.

The SatisfyImportsOnce method allows a part to have its imports filled without being added to the container. If the composition is successful, the part's imports will be filled, but the part's exports will not be available to other parts and no imports will be registered for recomposition.

CompositionContainer objects should always be disposed. When the Dispose method is called, the CompositionContainer object also disposes all the parts that it has created.

A CompositionContainer object that can be accessed from multiple threads must be constructed with the isThreadSafe parameter set to true. Performance will be slightly impaired, so false is preferred in single-threaded scenarios. The default is false.

Examples

In the following example, a CompositionContainer object is initialized with a catalog and is used to fill the imports of a part. This example uses the Attributed Programming Model.

    [Export]
    class MyAddin
    {
        public String myData { get { return "The data!"; } }
    }

    class MyProgram
    {
        [Import]
        public MyAddin myAddin { get; set; }
    }


    class Program
    {
        static void Main(string[] args)
        {
            AggregateCatalog catalog = new AggregateCatalog();
            catalog.Catalogs.Add(new AssemblyCatalog(typeof(MyAddin).Assembly));
            CompositionContainer _container = new CompositionContainer(catalog);
            MyProgram myProgram = new MyProgram();
            _container.SatisfyImportsOnce(myProgram);
            Console.WriteLine(myProgram.myAddin.myData);
            Console.ReadLine();
        }
    }

Version Information

Silverlight

Supported in: 5, 4

Platforms

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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.