Introduction : SendActivity, can be used to send requests to WCF services. The SendActivity activity enables you to participate in a conversation with a WCF service using a predefined message exchange pattern. The SendActivity activity is a blocking activity, meaning that workflow execution will be blocked until the activity completes execution. The SendActivity is used to call an operation exposed by a WCF service from an executing workflow instance. The Workflow Service generates a proxy for the call according to properties of the SendActivity, including the selected service contract and associated WCF configuration settings. The response from a SendActivity can be stored and used by the running workflow instance, including reported exceptions.

SendActivity Classes :

Step 1 : Open Visual Studio2010.
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Step 2 : Drag activity from Toolbox.

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Step 3 : Go to Solution Explorer and Right-click.


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Step 4 : 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 WorkflowConsoleApplication1
class Program
 {
 public sealed partial class Workflow1 : SequentialWorkflowActivity
{
public Workflow1()
{
InitializeComponent();
}
public static DependencyProperty sendActivity1__ReturnValueProperty = DependencyProperty.Register("sendActivity1__ReturnValue", ty(System.String), typeof(SendActivitySample.Workflow1));
public String sendActivity1__ReturnValue
{
get
 {
return ((string)(base.GetValue(SendActivitySample.Workflow1.sendActivity1__ReturnValueProperty)));
}
set
 {
base.SetValue(SendActivitySample.Workflow1.sendActivity1__ReturnValueProperty, value);
}
}
private void codeActivity1_ExecuteCode(object sender, EventArgs e)
{
Console.WriteLine(GetValue(Workflow1.sendActivity1__ReturnValueProperty));
}
}
}
}

Step 5 : Go to Workflow1.cs and select the Design option.

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Step 6 : Now go to the program's file and write the below code.

Code :

using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Web;
 using System.Runtime.Serialization;
 using System.ServiceModel;
 using System.Text;
 namespace DeclarativeServiceLibrary2
{
public class Class1
 {
public interface IMyService
 {
string GetResponse(string value);
}
public class MyService : IMyService
 {
 #region IMyService Members
public string GetResponse(string value)
{
return string.Format("Hello {0}!", value);
}
 #endregion
 }
}

Step 7 : Press F5 to run it.

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