DirectoryCatalog Constructor (String, String, ICompositionElement)

.NET Framework (current version)

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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.

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

public DirectoryCatalog(
	string path,
	string searchPattern,
	ICompositionElement definitionOrigin


Type: System.String

The path to the directory to scan for assemblies to add to the catalog.

The path must be absolute or relative to BaseDirectory.

Type: System.String

The search string. The format of the string should be the same as specified for the GetFiles method.

Type: System.ComponentModel.Composition.Primitives.ICompositionElement

The element used by diagnostics to identify the source for parts.

Exception Condition

The specified path is invalid (for example, it is on an unmapped drive).


path or searchPattern is null.


The caller does not have the required permission.


path is a zero-length string, contains only white space, or contains one or more implementation-specific invalid characters.


searchPattern does not contain a valid pattern.


The specified path, file name, or both exceed the system-defined maximum length. For example, on Windows-based computers, paths must be less than 248 characters and file names must be less than 260 characters.

.NET Framework
Available since 4.5
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