Parallel Class
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Parallel Class

.NET Framework (current version)
 

An activity that executes all child activities simultaneously and asynchronously.

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

System.Object
  System.Activities.Activity
    System.Activities.NativeActivity
      System.Activities.Statements.Parallel

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

NameDescription
System_CAPS_pubmethodParallel()

Creates a new instance of the Parallel activity.

NameDescription
System_CAPS_pubpropertyBranches

The child elements to be executed in parallel.

System_CAPS_protpropertyCacheId

Gets the identifier of the cache that is unique within the scope of the workflow definition.(Inherited from Activity.)

System_CAPS_pubpropertyCompletionCondition

Evaluates after any branch completes.

System_CAPS_pubpropertyDisplayName

Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking.(Inherited from Activity.)

System_CAPS_pubpropertyId

Gets an identifier that is unique in the scope of the workflow definition.(Inherited from Activity.)

System_CAPS_protpropertyImplementationVersion

Gets or sets the implementation version of the activity.(Inherited from NativeActivity.)

System_CAPS_pubpropertyVariables

The collection of contained variables.

NameDescription
System_CAPS_pubmethodEquals(Object)

Determines whether the specified object is equal to the current object.(Inherited from Object.)

System_CAPS_pubmethodGetHashCode()

Serves as the default hash function. (Inherited from Object.)

System_CAPS_pubmethodGetType()

Gets the Type of the current instance.(Inherited from Object.)

System_CAPS_pubmethodShouldSerializeDisplayName()

Indicates whether the DisplayName property should be serialized.(Inherited from Activity.)

System_CAPS_pubmethodToString()

Returns a String that contains the Id and DisplayName of the Activity.(Inherited from Activity.)

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
Available since 4.0

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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