Sum(TSource) Method (ParallelQuery(TSource), Func(TSource, Nullable(Single)))

Task Parallel System.Threading

Computes in parallel the sum of the sequence of values that are obtained by invoking a transform function on each element of the input sequence.

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

Syntax

Visual Basic (Declaration)
Public Shared Function Sum(Of TSource) ( _
	source As ParallelQuery(Of TSource), _
	selector As Func(Of TSource, Nullable(Of Single)) _
) As Nullable(Of Single)
C#
public static Nullable<float> Sum<TSource>(
	ParallelQuery<TSource> source,
	Func<TSource, Nullable<float>> selector
)

Parameters

source
Type: System.Linq..::.ParallelQuery<(Of <(TSource>)>)
A sequence of values to calculate the sum of.
selector
Type: System..::.Func<(Of <(TSource, Nullable<(Of <(Single>)>)>)>)
A transform function to apply to each element.

Type Parameters

TSource
The type of elements of source.

Return Value

The sum of the values in the sequence.

Exceptions

ExceptionCondition
System..::.ArgumentNullException source or selector is a null reference (Nothing in Visual Basic).
System..::.AggregateException One or more exceptions occurred during the evaluation of the query.
System..::.OperationCanceledException The query was canceled.

See Also