CompositionContainer Class

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

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Properties

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

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Methods

	Name	Description
	Compose	Executes composition on the container, including the changes in the specified CompositionBatch.
	Dispose()	Releases all resources used by the current instance of the CompositionContainer class.
	Dispose(Boolean)	Releases the unmanaged resources used by the CompositionContainer and optionally releases the managed resources.
	Equals(Object)	Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
	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.)
	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.)
	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.)
	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.)
	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.)
	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.)
	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.)
	GetExportedValues<T>()	Gets all the exported objects with the contract name derived from the specified type parameter. (Inherited from ExportProvider.)
	GetExportedValues<T>(String)	Gets all the exported objects with the specified contract name. (Inherited from ExportProvider.)
	GetExports(ImportDefinition)	Gets all exports that match the conditions of the specified import definition. (Inherited from ExportProvider.)
	GetExports(ImportDefinition, AtomicComposition)	Gets all exports that match the conditions of the specified import definition and composition. (Inherited from ExportProvider.)
	GetExports(Type, Type, String)	Gets all the exports with the specified contract name. (Inherited from ExportProvider.)
	GetExports<T>()	Gets all the exports with the contract name derived from the specified type parameter. (Inherited from ExportProvider.)
	GetExports<T>(String)	Gets all the exports with the specified contract name. (Inherited from ExportProvider.)
	GetExportsCore	Returns a collection of all exports that match the conditions in the specified ImportDefinition object. (Overrides ExportProvider.GetExportsCore(ImportDefinition, AtomicComposition).)
	GetHashCode	Serves as a hash function for a particular type. (Inherited from Object.)
	GetType	Gets the Type of the current instance. (Inherited from Object.)
	MemberwiseClone	Creates a shallow copy of the current Object. (Inherited from Object.)
	OnExportsChanged	Raises the ExportsChanged event. (Inherited from ExportProvider.)
	OnExportsChanging	Raises the ExportsChanging event. (Inherited from ExportProvider.)
	ReleaseExport(Export)	Releases the specified Export object from the CompositionContainer.
	ReleaseExport<T>(Lazy<T>)	Removes the specified export from composition and releases its resources if possible.
	ReleaseExports(IEnumerable<Export>)	Releases a set of Export objects from the CompositionContainer.
	ReleaseExports<T>(IEnumerable<Lazy<T>>)	Removes a collection of exports from composition and releases their resources if possible.
	ReleaseExports<T, TMetadataView>(IEnumerable<Lazy<T, TMetadataView>>)	Removes a collection of exports from composition and releases their resources if possible.
	SatisfyImportsOnce	Satisfies the imports of the specified ComposablePart object without registering it for recomposition.
	ToString	Returns a string that represents the current object. (Inherited from Object.)
	TryGetExports	Gets all the exports that match the conditions of the specified import. (Inherited from ExportProvider.)

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Events

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

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Extension Methods

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

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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.

See Also

Reference

System.ComponentModel.Composition.Hosting Namespace