ParallelEnumerable.GroupBy<'TSource, 'TKey> Method (ParallelQuery<'TSource>, Func<'TSource, 'TKey>, IEqualityComparer<'TKey>)

.NET Framework (current version)
 

Groups in parallel the elements of a sequence according to a specified key selector function and compares the keys by using a specified IComparer<'T>.

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

static member GroupBy<'TSource, 'TKey> : 
        source:ParallelQuery<'TSource> *
        keySelector:Func<'TSource, 'TKey> *
        comparer:IEqualityComparer<'TKey> -> ParallelQuery<IGrouping<'TKey, 'TSource>>

Parameters

source
Type: System.Linq.ParallelQuery<'TSource>

An OrderedParallelQuery<'TSource> that contains elements to sort.

keySelector
Type: System.Func<'TSource, 'TKey>

A function to extract a key from an element.

comparer
Type: System.Collections.Generic.IEqualityComparer<'TKey>

An IComparer<'T> to compare keys.

Return Value

Type: System.Linq.ParallelQuery<IGrouping<'TKey, 'TSource>>

A sequence of groups that are sorted descending according to TKey.

Type Parameters

TSource

The type of elements of source.

TKey

The type of the key returned by keySelector>.

Exception Condition
OperationCanceledException

The query was canceled with the token passed in through WithCancellation.

ArgumentNullException

source or action is a null reference (Nothing in Visual Basic).

AggregateException

One or more exceptions occurred during the evaluation of the query.

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
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