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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)

member GetExportedValueOrDefault : 
        contractName:string -> 'T 

Type Parameters


The type of the exported object to return.


Type: System.String

The contract name of the exported object to return, or a null reference (Nothing in Visual Basic) 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 a null reference (Nothing in Visual Basic) 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

Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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