ForEach(TSource) Method (IEnumerable(TSource), ParallelOptions, Action(TSource, ParallelLoopState, Int64))

Task Parallel System.Threading

Executes a for each operation on an IEnumerable<(Of <(TSource>)>) in which iterations may run in parallel.

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

Syntax

Visual Basic (Declaration)
Public Shared Function ForEach(Of TSource) ( _
	source As IEnumerable(Of TSource), _
	parallelOptions As ParallelOptions, _
	body As Action(Of TSource, ParallelLoopState, Long) _
) As ParallelLoopResult
C#
public static ParallelLoopResult ForEach<TSource>(
	IEnumerable<TSource> source,
	ParallelOptions parallelOptions,
	Action<TSource, ParallelLoopState, long> body
)

Parameters

source
Type: System.Collections.Generic..::.IEnumerable<(Of <(TSource>)>)
An enumerable data source.
parallelOptions
Type: System.Threading.Tasks..::.ParallelOptions
A ParallelOptions instance that configures the behavior of this operation.
body
Type: System..::.Action<(Of <(TSource, ParallelLoopState, Int64>)>)
The delegate that is invoked once per iteration.

Type Parameters

TSource
The type of the data in the source.

Return Value

A ParallelLoopResult structure that contains information on what portion of the loop completed.

Remarks

The body delegate is invoked once for each element in the source enumerable. It is provided with the following parameters: the current element, a ParallelLoopState instance that may be used to break out of the loop prematurely, and the current element's index (an Int64).

Exceptions

ExceptionCondition
System..::.ArgumentNullExceptionThe exception that is thrown when the source argument is null.
System..::.ArgumentNullExceptionThe exception that is thrown when the parallelOptions argument is null.
System..::.ArgumentNullExceptionThe exception that is thrown when the body argument is null.
System..::.OperationCanceledExceptionThe exception that is thrown when the CancellationToken in the parallelOptions argument is set
System..::.AggregateExceptionThe exception that is thrown to contain an exception thrown from one of the specified delegates.
System..::.ObjectDisposedExceptionThe exception that is thrown when the the CancellationTokenSource associated with the the CancellationToken in the parallelOptions has been disposed.

See Also