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ExportProvider.GetExportedValueOrDefault<T> Method (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.

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

public T GetExportedValueOrDefault<T>(
	string contractName

Type Parameters


The type of the exported object to return.


Type: System.String
The contract name of the exported object to return, or null or an empty string ("") to use the default contract name.

Return Value

Type: T
The exported object with the specified contract name, if found; otherwise, the default value for T.


There is more than one exported object with the specified contract name in the CompositionContainer.


The CompositionContainer object has been disposed of.


The underlying exported object cannot be cast to T.


An error occurred during composition. Errors will contain a collection of errors that occurred.

If the exported object is not found, this method returns the appropriate default value for T; for example, zero for integer types, false for Boolean types, and null for reference types.

The default contract name is the result of calling the GetContractName method on T.

The contract name is compared by using the Ordinal property to perform a case-sensitive, non-linguistic comparison.

.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

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.