DirectoryCatalog Class

Definition

Namespace:

System.ComponentModel.Composition.Hosting

Assembly:

System.ComponentModel.Composition.dll

Package:

System.ComponentModel.Composition v9.0.0

Source:

DirectoryCatalog.cs

Discovers attributed parts in the assemblies in a specified directory.

public ref class DirectoryCatalog : System::ComponentModel::Composition::Primitives::ComposablePartCatalog, System::ComponentModel::Composition::Hosting::INotifyComposablePartCatalogChanged, System::ComponentModel::Composition::Primitives::ICompositionElement

public class DirectoryCatalog : System.ComponentModel.Composition.Primitives.ComposablePartCatalog, System.ComponentModel.Composition.Hosting.INotifyComposablePartCatalogChanged, System.ComponentModel.Composition.Primitives.ICompositionElement

type DirectoryCatalog = class
    inherit ComposablePartCatalog
    interface INotifyComposablePartCatalogChanged
    interface ICompositionElement

Public Class DirectoryCatalog
Inherits ComposablePartCatalog
Implements ICompositionElement, INotifyComposablePartCatalogChanged

Inheritance

Object

ComposablePartCatalog

DirectoryCatalog

Implements

INotifyComposablePartCatalogChanged ICompositionElement

Examples

The following example creates a DirectoryCatalog object that searches the directory the application runs from for parts. It uses a simple import to test the catalog. To fulfill this import, a DLL in the directory must have a matching export, as illustrated in the second code block.

public class Test2
{
    [Import]
    public Test1 data { get; set; }
}

class Program
{
    static void Main(string[] args)
    {
        DirectoryCatalog catalog = new DirectoryCatalog(".");
        CompositionContainer container = new CompositionContainer(catalog);
        Test2 test = new Test2();
        container.SatisfyImportsOnce(test);
        Console.WriteLine(test.data.data);
        Console.ReadLine();
    }
}

Public Class Test2
    <Import()>
    Public Property data As Test1
End Class

Sub Main()
    Dim catalog As New DirectoryCatalog(".")
    Dim container As New CompositionContainer(catalog)
    Dim test As New Test2()
    container.SatisfyImportsOnce(test)
    Console.WriteLine(test.data.data)
    Console.ReadLine()
End Sub

To create the matching export, the following code must be in a DLL file. To create a DLL file in Visual Studio, add a new project of the type "Class Library" to your solution, and place this code in it.

[Export]
public class Test1
{
    public String data = "The data!";
}

<Export()>
Public Class Test1
    Public ReadOnly Property data As String
        Get
            Return "The data!"
        End Get
    End Property
End Class

Remarks

You can use a DirectoryCatalog object to parse the contents of a designated directory. Any attributed parts contained in dynamic link library (DLL) files are extracted and made available through the catalog.To restrict parsing to specific DLLs, you can specify a search pattern by using the same syntax as the Directory.GetFiles method.

Warning

The designated directory should not allow access to non-administrators. For example, using a folder that contains temporary Internet files could create vulnerabilities in your application.

This type implements the IDisposable interface. When you have finished using the type, you should dispose of it either directly or indirectly. To dispose of the type directly, call its Dispose method in a try/catch block. To dispose of it indirectly, use a language construct such as using (in C#) or Using (in Visual Basic). For more information, see the "Using an Object that Implements IDisposable" section in the IDisposable interface topic.

Constructors

DirectoryCatalog(String, ICompositionElement)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on all the DLL files in the specified directory path with the specified source for parts.
DirectoryCatalog(String, ReflectionContext, ICompositionElement)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on all the DLL files in the specified directory path, in the specified reflection context.
DirectoryCatalog(String, ReflectionContext)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on all the DLL files in the specified directory path, in the specified reflection context.
DirectoryCatalog(String, String, ICompositionElement)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on the specified search pattern in the specified directory path with the specified source for parts.
DirectoryCatalog(String, String, ReflectionContext, ICompositionElement)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on the specified search pattern in the specified directory path, using the specified reflection context.
DirectoryCatalog(String, String, ReflectionContext)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on the specified search pattern in the specified directory path, using the specified reflection context.
DirectoryCatalog(String, String)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects that match a specified search pattern in the specified directory path.
DirectoryCatalog(String)	Initializes a new instance of the DirectoryCatalog class by using ComposablePartDefinition objects based on all the DLL files in the specified directory path.

Properties

FullPath	Gets the translated absolute path observed by the DirectoryCatalog object.
LoadedFiles	Gets the collection of files currently loaded in the catalog.
Parts	Gets the part definitions that are contained in the catalog. (Inherited from ComposablePartCatalog)
Path	Gets the path observed by the DirectoryCatalog object.
SearchPattern	Gets the search pattern that is passed into the constructor of the DirectoryCatalog object.

Methods

Dispose()	Releases all resources used by the ComposablePartCatalog. (Inherited from ComposablePartCatalog)
Dispose(Boolean)	Releases the unmanaged resources used by the DirectoryCatalog and optionally releases the managed resources.
Equals(Object)	Determines whether the specified object is equal to the current object. (Inherited from Object)
GetEnumerator()	Returns an enumerator that iterates through the catalog.
GetExports(ImportDefinition)	Gets the export definitions that match the constraint expressed by the specified import definition.
GetHashCode()	Serves as the default hash function. (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)
OnChanged(ComposablePartCatalogChangeEventArgs)	Raises the Changed event.
OnChanging(ComposablePartCatalogChangeEventArgs)	Raises the Changing event.
Refresh()	Refreshes the ComposablePartDefinition objects with the latest files in the directory that match the search pattern.
ToString()	Gets a string representation of the directory catalog.

Events

Changed	Occurs when the contents of the catalog has changed.
Changing	Occurs when the catalog is changing.

Explicit Interface Implementations

ICompositionElement.DisplayName	Gets the display name of the directory catalog.
ICompositionElement.Origin	Gets the composition element from which the directory catalog originated.
IEnumerable.GetEnumerator()	Returns an enumerator that iterates through the catalog. (Inherited from ComposablePartCatalog)

Extension Methods

ToFrozenDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Creates a FrozenDictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector function.
ToFrozenDictionary<TSource,TKey,TElement>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TElement>, IEqualityComparer<TKey>)	Creates a FrozenDictionary<TKey,TValue> from an IEnumerable<T> according to specified key selector and element selector functions.
ToFrozenSet<T>(IEnumerable<T>, IEqualityComparer<T>)	Creates a FrozenSet<T> with the specified values.
ToImmutableArray<TSource>(IEnumerable<TSource>)	Creates an immutable array from the specified collection.
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>, IEqualityComparer<TKey>)	Constructs an immutable dictionary based on some transformation of a sequence.
ToImmutableDictionary<TSource,TKey>(IEnumerable<TSource>, Func<TSource,TKey>)	Constructs an immutable dictionary from an existing collection of elements, applying a transformation function to the source keys.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>, IEqualityComparer<TValue>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key and value comparers.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IEqualityComparer<TKey>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents by using the specified key comparer.
ToImmutableDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)	Enumerates and transforms a sequence, and produces an immutable dictionary of its contents.
ToImmutableHashSet<TSource>(IEnumerable<TSource>, IEqualityComparer<TSource>)	Enumerates a sequence, produces an immutable hash set of its contents, and uses the specified equality comparer for the set type.
ToImmutableHashSet<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable hash set of its contents.
ToImmutableList<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable list of its contents.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>, IEqualityComparer<TValue>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key and value comparers.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>, IComparer<TKey>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents by using the specified key comparer.
ToImmutableSortedDictionary<TSource,TKey,TValue>(IEnumerable<TSource>, Func<TSource,TKey>, Func<TSource,TValue>)	Enumerates and transforms a sequence, and produces an immutable sorted dictionary of its contents.
ToImmutableSortedSet<TSource>(IEnumerable<TSource>, IComparer<TSource>)	Enumerates a sequence, produces an immutable sorted set of its contents, and uses the specified comparer.
ToImmutableSortedSet<TSource>(IEnumerable<TSource>)	Enumerates a sequence and produces an immutable sorted set of its contents.
CreateCompositionService(ComposablePartCatalog)	Creates a new composition service by using the specified catalog as a source for exports.
Filter(ComposablePartCatalog, Func<ComposablePartDefinition,Boolean>)	Filters the specified catalog with the specified filter function.