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Parallel.ForEach<TSource> Method (IEnumerable<TSource>, ParallelOptions, Action<TSource, ParallelLoopState>)

Executes a foreach (For Each in Visual Basic) operation on an IEnumerable in which iterations may run in parallel, loop options can be configured, and the state of the loop can be monitored and manipulated.

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

public static ParallelLoopResult ForEach<TSource>(
	IEnumerable<TSource> source,
	ParallelOptions parallelOptions,
	Action<TSource, ParallelLoopState> body
)

Type Parameters

TSource

The type of the data in the source.

Parameters

source
Type: System.Collections.Generic.IEnumerable<TSource>

An enumerable data source.

parallelOptions
Type: System.Threading.Tasks.ParallelOptions

An object that configures the behavior of this operation.

body
Type: System.Action<TSource, ParallelLoopState>

The delegate that is invoked once per iteration.

Return Value

Type: System.Threading.Tasks.ParallelLoopResult
A structure that contains information about which portion of the loop completed.

ExceptionCondition
OperationCanceledException

The CancellationToken in the parallelOptions argument is canceled

ArgumentNullException

The source argument is null.

-or-

The parallelOptions argument is null.

-or-

The body argument is null.

AggregateException

The exception that contains all the individual exceptions thrown on all threads.

ObjectDisposedException

The CancellationTokenSource associated with the CancellationToken in the parallelOptions has been disposed.

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

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4

.NET Framework Client Profile

Supported in: 4

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1

Windows Phone 8.1, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

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