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)

public static ParallelQuery<IGrouping<TKey, TSource>> GroupBy<TSource, TKey>(
	this ParallelQuery<TSource> source,
	Func<TSource, TKey> keySelector,
	IEqualityComparer<TKey> comparer
)

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
Return to top
Show: