ParallelEnumerable::ThenByDescending<TSource, TKey> Method (OrderedParallelQuery<TSource>^, Func<TSource, TKey>^)

.NET Framework (current version)

Performs in parallel a subsequent ordering of the elements in a sequence in descending order, according to a key.

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

Syntax

public:
generic<typename TSource, typename TKey>
[ExtensionAttribute]
static OrderedParallelQuery<TSource>^ ThenByDescending(
	OrderedParallelQuery<TSource>^ source,
	Func<TSource, TKey>^ keySelector
)

Parameters

source: Type: System.Linq::OrderedParallelQuery<TSource>^
An OrderedParallelQuery{TSource} that contains elements to sort.

keySelector: Type: System::Func<TSource, TKey>^
A function to extract a key from an element.

Return Value

Type: System.Linq::OrderedParallelQuery<TSource>^

A sequence whose elements are sorted descending according to a key.

Type Parameters

TSource: The type of elements of source.

TKey: The type of the key returned by keySelector.

Exceptions

Exception	Condition
ArgumentNullException	source or keySelector is a null reference (Nothing in Visual Basic).
OperationCanceledException	The query was canceled with the token passed in through WithCancellation.
AggregateException	One or more exceptions occurred during the evaluation of the query.

Remarks

In contrast to the sequential implementation, this is not a stable sort. See the remarks for OrderBy<TSource, TKey> for an approach to implementing a stable sort.

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