ParallelEnumerable.Single<TSource> Method (ParallelQuery<TSource>, Func<TSource, Boolean>)

.NET Framework (current version)

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Returns the only element of a parallel sequence that satisfies a specified condition, and throws an exception if more than one such element exists.

Namespace: System.Linq
Assembly: System.Core (in System.Core.dll)

Syntax

C++

public static TSource Single<TSource>(
	this 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: TSource

The single element of the input sequence that satisfies a condition.

Type Parameters

TSource: The type of the elements of source.

Exceptions

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	No element satisfies the condition in predicate. -or- More than one element satisfies the condition in predicate.

Version Information

Universal Windows Platform
Available since 8
.NET Framework
Available since 4.0
Portable Class Library
Supported in: portable .NET platforms
Windows Phone
Available since 8.1