ParallelForEach<T> Class
Enumerates the elements of a collection and executes an embedded statement for each element of the collection in parallel.
Assembly: System.Activities (in System.Activities.dll)
System.Activities::Activity
System.Activities::NativeActivity
System.Activities.Statements::ParallelForEach<T>
| Name | Description | |
|---|---|---|
![]() | ParallelForEach<T>() | Creates a new instance of the ParallelForEach<T> class. |
| Name | Description | |
|---|---|---|
![]() | Body | The ActivityAction that is executed once for every value contained in the Values collection. |
![]() | CacheId | Gets the identifier of the cache that is unique within the scope of the workflow definition.(Inherited from Activity.) |
![]() | CompletionCondition | Evaluated after each iteration completes. |
![]() | DisplayName | Gets or sets an optional friendly name that is used for debugging, validation, exception handling, and tracking.(Inherited from Activity.) |
![]() | Id | Gets an identifier that is unique in the scope of the workflow definition.(Inherited from Activity.) |
![]() | ImplementationVersion | Gets or sets the implementation version of the activity.(Inherited from NativeActivity.) |
![]() | Values | The collection of values used as parameters for each iteration of the activity contained in the Body. |
| Name | Description | |
|---|---|---|
![]() | Equals(Object^) | Determines whether the specified object is equal to the current object.(Inherited from Object.) |
![]() | GetHashCode() | Serves as the default hash function. (Inherited from Object.) |
![]() | GetType() | |
![]() | ShouldSerializeDisplayName() | Indicates whether the DisplayName property should be serialized.(Inherited from Activity.) |
![]() | ToString() | Returns a String that contains the Id and DisplayName of the Activity.(Inherited from Activity.) |
The embedded statements are scheduled together and run asynchronously, but unless the scheduled activites themselves are asynchronous (such as messaging activities, InvokeMethod, or activities that derive from AsyncCodeActivity), they do not run on separate threads, so each successive activity will only execute when the previously scheduled activity completes or goes idle. If none of the child activities of this activity are asynchronous or go idle, this activity execute in the same way that a ForEach<T> activity does.
The following code sample demonstrates creating a ParallelForEach<T> activity. This example is from the Corporate Purchase Process sample.
// invite all vendors and wait for their proposals new ParallelForEach<Vendor> { DisplayName = "Get vendor proposals", Values = new InArgument<IEnumerable<Vendor>>(ctx =>this.Rfp.Get(ctx).InvitedVendors), Body = new ActivityAction<Vendor>() { Argument = iterationVariableVendor, Handler = new Sequence { Variables = { tmpValue }, Activities = { // waits for a vendor proposal (creates a bookmark for a vendor) new WaitForVendorProposal { VendorId = new LambdaValue<int>(ctx =>iterationVariableVendor.Get(ctx).Id) , Result = new OutArgument<double>(tmpValue) }, // after the vendor proposal is received, it is registered in the Request for Proposals new InvokeMethod { TargetObject = new InArgument<RequestForProposal>(ctx =>this.Rfp.Get(ctx)), MethodName = "RegisterProposal", Parameters = { new InArgument<Vendor>(iterationVariableVendor), new InArgument<double>(tmpValue) } }, } } } },
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.


