ExportProvider.GetExportedValueOrDefault Method
Definition
Important
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Gets a specified exported object or a default value if it is unavailable.
Overloads
| GetExportedValueOrDefault<T>() |
Gets the exported object with the contract name derived from the specified type parameter or the default value for the specified type, or throws an exception if there is more than one matching exported object. |
| GetExportedValueOrDefault<T>(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. |
GetExportedValueOrDefault<T>()
Gets the exported object with the contract name derived from the specified type parameter or the default value for the specified type, or throws an exception if there is more than one matching exported object.
public:
generic <typename T>
T GetExportedValueOrDefault();public T? GetExportedValueOrDefault<T> ();public T GetExportedValueOrDefault<T> ();member this.GetExportedValueOrDefault : unit -> 'TPublic Function GetExportedValueOrDefault(Of T) () As TType Parameters
- T
The type of the exported object to return. The contract name is also derived from this type parameter.
Returns
The exported object with the contract name derived from T, if found; otherwise, the default value for T.
Exceptions
There is more than one exported object with the contract name derived from T 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.
Remarks
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 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.
Applies to
GetExportedValueOrDefault<T>(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.
public:
generic <typename T>
T GetExportedValueOrDefault(System::String ^ contractName);public T? GetExportedValueOrDefault<T> (string? contractName);public T GetExportedValueOrDefault<T> (string contractName);member this.GetExportedValueOrDefault : string -> 'TPublic Function GetExportedValueOrDefault(Of T) (contractName As String) As TType Parameters
- T
The type of the exported object to return.
Parameters
- contractName
- String
The contract name of the exported object to return, or null or an empty string ("") to use the default contract name.
Returns
The exported object with the specified contract name, if found; otherwise, the default value for T.
Exceptions
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.
Remarks
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.
