Lifetime Events in Workflow

Introduction : Windows Workflow offers two workflow execution styles out of the box: sequential and event-driven. A sequential workflow completes one activity and moves to the next, executing a sequence of consecutive steps. Event-driven workflows model as a state machine. A state machine consists of a set of states (including an initial state and a final state), and a set of events. The state machine is always in one of the defined states, and cannot transition to a new state until an event arrives. Workflow Runtime exposes a number of events we can use to detect changes in a running workflow.

Following Events are given below :

WorkflowAborted.
WorkflowCreated.
WorkflowCompleted.
WorkflowStarted.

Step 1 : Open Visual Studio 2010.

Go to File->New->Project.
Select Sequential Workflow Library.

Step 2 : Now drag activity from Toolbox.

Drag Sequence, Code Activity.

Step 3 : Now go to Solution Explorer and right-click

Add -> New Item->Activity ( Code Separation).
When we click OK then the following design window open.

Step 4 : Now go to program.cs option and 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;
using System.Workflow.Activities;
namespace WorkflowConsoleApplication16
{
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);
waitHandle.Set();
};
Console.WriteLine("Running Workflow Events :");
Console.WriteLine("Workflow created");
Console.WriteLine("Workflow started");
Console.ReadLine();
WorkflowInstance instance = workflowRuntime.CreateWorkflow(typeof(WorkflowConsoleApplication16.Workflow1));
instance.Start();
waitHandle.WaitOne();
}
}
}
}

Step 5 : Now go to Activity1.xaml.cs file and define the event and code for the Sequential Workflow.

Code :

using System;
using System.ComponentModel;
using System.ComponentModel.Design;
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;
namespace WorkflowConsoleApplication16
{
public partial class Activity1 : SequenceActivity
{
private void codeActivity1_ExecuteCode(object sender, EventArgs e)
{
Console.WriteLine("Executing...");
}
static void runtime_WorkflowIdled(object sender, WorkflowEventArgs e)
{
Console.WriteLine("Workflow idled");
}
static void runtime_WorkflowCreated(object sender,
WorkflowEventArgs e)
{
Console.WriteLine("Workflow created");
}
static void runtime_WorkflowTerminated(object sender,WorkflowTerminatedEventArgs e)
{
Console.WriteLine("Workflow terminated");
Console.WriteLine("\tException: " + e.Exception.Message);
Console.ReadLine();
}
}
}

Step 6 : Now Build the application and check the error are present or not.

Step 7 : Now again go to Program.cs file and define the following code for the WorkflowRuntimeEvent.

Code :
runtime.WorkflowCreated += new EventHandler<WorkflowEventArgs>(runtime_WorkflowCreated)
runtime.WorkflowIdled += new EventHandler<WorkflowEventArgs>(runtime_WorkflowIdled);
AutoResetEvent waitHandle = new AutoResetEvent(false);

Step 8 : Press F5 and run the application.