ParallelEnumerable.First(Of TSource) Method (ParallelQuery(Of TSource), Func(Of TSource, Boolean))

.NET Framework (current version)
 
System_CAPS_noteNote

The .NET API Reference documentation has a new home. Visit the .NET API Browser on docs.microsoft.com to see the new experience.

Returns the first element in a parallel sequence that satisfies a specified condition.

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

<ExtensionAttribute>
Public Shared Function First(Of TSource) (
	source As ParallelQuery(Of TSource),
	predicate As Func(Of TSource, Boolean)
) As TSource

Parameters

source
Type: System.Linq.ParallelQuery(Of TSource)

The sequence to return an element from.

predicate
Type: System.Func(Of TSource, Boolean)

A function to test each element for a condition.

Return Value

Type: TSource

The first element in the sequence that passes the test in the specified predicate function.

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

No element in source satisfies the condition in predicate.

If the query is not ordered, then the first element is non-deterministic. For more information, see Order Preservation in PLINQ.

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
Return to top
Show: