ParallelEnumerable::SingleOrDefault<TSource> Method (ParallelQuery<TSource>^, Func<TSource, Boolean>^)
Returns the only element of a parallel sequence that satisfies a specified condition or a default value if no such element exists; this method throws an exception if more than one element satisfies the condition.
Assembly: System.Core (in System.Core.dll)
public: generic<typename TSource> [ExtensionAttribute] static TSource SingleOrDefault( ParallelQuery<TSource>^ source, Func<TSource, bool>^ predicate )
Parameters
- source
-
Type:
System.Linq::ParallelQuery<TSource>^
The sequence to return the single element of.
- predicate
-
Type:
System::Func<TSource, Boolean>^
A function to test an element for a condition.
Return Value
Type: TSourceThe single element of the input sequence that satisfies the condition, or default() if no such element is found.
Type Parameters
- TSource
The type of the elements of source.
| Exception | Condition |
|---|---|
| OperationCanceledException | The query was canceled with the token passed in through WithCancellation. |
| ArgumentNullException | source or predicate is a null reference (Nothing in Visual Basic). |
| AggregateException | One or more exceptions occurred during the evaluation of the query. |
| InvalidOperationException | source is empty or multiple elements are returned. |
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1