Parallel Class

An activity that executes all child activities simultaneously and asynchronously.

Namespace:  System.Activities.Statements
Assembly:  System.Activities (in System.Activities.dll)

[ContentPropertyAttribute("Branches")]
public sealed class Parallel : NativeActivity

The Parallel type exposes the following members.

  NameDescription
Public methodParallelCreates a new instance of the Parallel activity.
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  NameDescription
Public propertyBranchesThe child elements to be executed in parallel.
Protected propertyCacheIdGets the identifier of the cache that is unique within the scope of the workflow definition. (Inherited from Activity.)
Protected propertyCanInduceIdleGets or sets a value that indicates whether the activity can cause the workflow to become idle. (Inherited from NativeActivity.)
Public propertyCompletionConditionEvaluates after any branch completes.
Protected propertyConstraintsGets a collection of Constraint activities that can be configured to provide validation for the Activity. (Inherited from Activity.)
Public propertyDisplayNameGets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking. (Inherited from Activity.)
Public propertyIdGets an identifier that is unique in the scope of the workflow definition. (Inherited from Activity.)
Protected propertyImplementationThe execution logic of the activity. (Inherited from NativeActivity.)
Public propertyVariablesThe collection of contained variables.
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  NameDescription
Protected methodAbortWhen implemented in a derived class, takes actions in response to the activity being aborted. (Inherited from NativeActivity.)
Protected methodCacheMetadata(ActivityMetadata)Not implemented. Use the CacheMetadata(NativeActivityMetadata) method instead. (Inherited from NativeActivity.)
Protected methodCacheMetadata(NativeActivityMetadata)Creates and validates a description of the activity’s arguments, variables, child activities, and activity delegates. (Inherited from NativeActivity.)
Protected methodCancelWhen implemented in a derived class, runs logic to cause graceful early completion of the activity. (Inherited from NativeActivity.)
Public methodEquals(Object)Determines whether the specified Object is equal to the current Object. (Inherited from Object.)
Protected methodExecuteWhen implemented in a derived class, runs the activity’s execution logic. (Inherited from NativeActivity.)
Protected methodFinalizeAllows an object to try to free resources and perform other cleanup operations before it is reclaimed by garbage collection. (Inherited from Object.)
Public methodGetHashCodeServes as a hash function for a particular type. (Inherited from Object.)
Public methodGetTypeGets the Type of the current instance. (Inherited from Object.)
Protected methodMemberwiseCloneCreates a shallow copy of the current Object. (Inherited from Object.)
Public methodShouldSerializeDisplayNameIndicates whether the DisplayName property should be serialized. (Inherited from Activity.)
Public methodToStringReturns a String that contains the Id and DisplayName of the Activity. (Inherited from Activity.)
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A Parallel activity operates by simultaneously scheduling each Activity in its Branches collection at the start. It completes when all of its Branches complete or when its CompletionCondition property evaluates to true. While all the Activity objects run asynchronously, they do not execute on separate threads, so each successive activity only executes when the previously scheduled activity completes or goes idle. If none of the child activities of this activity go idle, this activity execute in the same way that a Sequence activity does.

The following code sample demonstrates creating a Parallel activity. This example is from the Cancellation Handler on Compensable Activity sample.


return new Parallel
{
    // Timeout from branch causes other branch to cancel.
    CompletionCondition = true,

    Branches =
    {
        // Delay Branch
        new Sequence
        {
            Activities =
            {
                new WriteLine { Text = "Branch1: Body is about to Delay 2secs transferring execution to Branch2" },
                new Delay
                {
                    Duration = TimeSpan.FromSeconds(2)
                },
                new WriteLine { Text = "Branch1: Body is about to complete causing Branch2 to cancel.." },
            }
        },


.NET Framework

Supported in: 4

.NET Framework Client Profile

Supported in: 4

Windows 7, Windows Vista SP1 or later, Windows XP SP3, Windows Server 2008 (Server Core not supported), Windows Server 2008 R2 (Server Core supported with SP1 or later), Windows Server 2003 SP2

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

Any public static (Shared in Visual Basic) members of this type are thread safe. Any instance members are not guaranteed to be thread safe.
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