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

T

The type of the exported object to return.

Parameters

contractName
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.

ExceptionCondition
ImportCardinalityMismatchException

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

ObjectDisposedException

The CompositionContainer object has been disposed of.

CompositionContractMismatchException

The underlying exported object cannot be cast to T.

CompositionException

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: 4.6, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library
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