ReplicatorActivity in Workflow

In this article we add a DelayActivity with a random timeout just to show that the ReplicatorActivity is really running in parallel mode.

Introduction : The Replicator Activity enables you to create an arbitrary number of instances of a single activity during run time. Each ReplicatorActivity can contain only one child activity, but the child can be a composite activity. The Replicator Activity  finishes when all child activities have finished. The Replicator Activity can be use in two way.

• Sequence Type.
• Parallel Type.

When we use the Unit Condition property to stop execution of the Replicator Activity before the completion of the child activity instance. The Replicator Activity is similar to a ForEach statement in code.

Step 1 : Open Visual Studio 2010.

• Go to File-> New-> Project.
• Select Sequential Workflow Console Application.

Step 2 : Drag activity form Toolbox.

• Drag Replicator, Sequence, Delay, Code activity.

Step 3 : Now we select Replicator Activity and right -click.

• Go to the properties option and define InitialChildData, Execution Type.

Step 4 :  Again select the Delay activity and right-click.

• Define TimeOutDuration.

Step 5 : Go to the Solution Explorer and select program.cs.

• Write the below code.

Code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading;
using System.Workflow.Runtime;
using System.Workflow.Runtime.Hosting;
namespace WorkflowConsoleApplication17
{
    class Program
    {
        static void Main(string[] args)
        {
            using (WorkflowRuntime workflowRuntime = new WorkflowRuntime())
            {
                AutoResetEvent waitHandle = new AutoResetEvent(false);
                workflowRuntime.WorkflowCompleted += delegate(object sender, WorkflowCompletedEventArgs e) { waitHandle.Set(); };
                workflowRuntime.WorkflowTerminated += delegate(object sender, WorkflowTerminatedEventArgs e)
                {
                    Console.WriteLine(e.Exception.Message);
                    Console.ReadLine();
                    waitHandle.Set();
                };
                WorkflowInstance instance = workflowRuntime.CreateWorkflow(typeof(WorkflowConsoleApplication17.Workflow1));
                instance.Start();
                waitHandle.WaitOne();
            }
        }
    }
}
 

Step 6 : Go to Workflow1.Designer.cs option and right a code for the DependencyProperty that is created using the DependencyProperty.RegisterAttached() function.

Code :

public static DependencyProperty LoopValueProperty = DependencyProperty.RegisterAttached("LoopValue", typeof(int), typeof(Workflow1));

Step 7 : Go to Workflow1.cs[Design] and select code activity.

• Double-click in code activity define the ReplicatorActivity works in sequential mode.

Code :

private void codeActivity1_ExecuteCode(object sender, EventArgs e)
        {
            int value = (int)replicatorActivity1.CurrentChildData[replicatorActivity1.CurrentIndex];
            Console.WriteLine("Loop value = {1}", value);
        }
        private void codeActivity1_ExecuteCode_1(object sender, EventArgs e)
        {
            Activity activity = (Activity)sender;
            int value = (int)activity.Parent.GetValue(LoopValueProperty);
            Console.WriteLine("The current value = {0}", value);
        }

Step 8 : GO to Workflow1.Designer.cs option and define the complete code for the Parallel and Sequence mode.

Code :

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
using System.Collections.Generic;
using System.Collections;
using System.Linq;
using System.Workflow.ComponentModel.Compiler;
using System.Workflow.ComponentModel.Serialization;
using System.Workflow.ComponentModel;
using System.Workflow.ComponentModel.Design;
using System.Workflow.Runtime;
using System.Workflow.Activities;
using System.Workflow.Activities.Rules;
using System.Data;
using System.Diagnostics;
namespace WorkflowConsoleApplication17
{
    public sealed partial class Workflow1 : SequentialWorkflowActivity
    {
        public Workflow1()
        {
            InitializeComponent();
        }
        public static DependencyProperty LoopValueProperty = DependencyProperty.RegisterAttached("LoopValue", typeof(int), typeof(Workflow1));
        private void replicatorActivity1_Initialized_1(object sender, EventArgs e)
        {
            ReplicatorActivity replicator = (ReplicatorActivity)sender;
            replicator.InitialChildData = new List<int>(Enumerable.Range(1, 5));
        }
        private void delayActivity1_InitializeTimeoutDuration(object sender, EventArgs e)
        {
            DelayActivity delay = (DelayActivity)sender;
            Random random = new Random();
            delay.TimeoutDuration = TimeSpan.FromSeconds(random.Next(5));
        }
        private void replicatorActivity1_ChildInitialized(object sender, ReplicatorChildEventArgs e)
        {
            e.Activity.SetValue(LoopValueProperty, e.InstanceData);
        }
        private void codeActivity1_ExecuteCode(object sender, EventArgs e)
        {
            int value = (int)replicatorActivity1.CurrentChildData[replicatorActivity1.CurrentIndex];
            Console.WriteLine("Loop value = {1}", value);
        }
        private void codeActivity1_ExecuteCode_1(object sender, EventArgs e)
        {
            Activity activity = (Activity)sender;
            int value = (int)activity.Parent.GetValue(LoopValueProperty);
            Console.WriteLine("The current value = {0}", value);
        }
        public IList replicatorActivity1_InitialChildData1 = default(System.Collections.IList);
    }
}

Step 9 : Press F5 and run the application.