Web Services in Workflow

Introduction : The Windows Workflow Foundation framework supports Web service interoperability. This includes the ability to expose a Workflow as Web service to ASP.NET clients and to other Workflows. Windows Workflow Foundation supports publishing a Workflow as an ASP.NET Web service on a Web server or server farm running ASP.NET on Internet Information Services (IIS). The Windows Workflow Foundation base activity library contains the WebServiceInputActivity and WebServiceOutputActivity, which enable a Workflow to be used as Web service end points. A Web service receives a request, performs some appropriate processing, and returns a response.

Creating a Workflow Service :

Step 1 : Open Visual Studio 2010.

Go to File->New->Project.
Select WCF Workflow Service Application.
When we click on the OK Button, the following Activities will show.

Define the Service :

Step 2 : Go to Solution Explorer and right-click.

Select Add->New Item->Class.
Class1.cs file open.
Write the below code.

Code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Runtime.Serialization;
using System.ServiceModel;
namespace book
{
[ServiceContract]
public interface ibook
{
[OperationContract]
binfo LookupBook(bookSearch request);
}
[MessageContract(IsWrapped = false)]
public class bookSearch
{
private String _ISBN
private String _Title;
private String _Author;
public bookSearch()
{
}
public bookSearch(String title, String author, String isbn)
{

_Title = title;
_Author = author;
_ISBN = isbn;
}
#region Public Properties
[MessageBodyMember]
public String Title
{
get { return _Title; }
set { _Title = value; }
}
[MessageBodyMember]
public String Author
{
get { return _Author; }
set { _Author = value; }
}
[MessageBodyMember]
public String ISBN
{
get { return _ISBN; }
set { _ISBN = value; }
}
#endregion Public Properties
}

[MessageContract(IsWrapped = false)]
public class binfo
{
private Guid _InventoryID;

private String _ISBN;|
private String _Title;
private String _Author;
private String _Status;
public binfo()
{
}
public binfo(String title, String author, String isbn,
String status)
{
_Title = title;
_Author = author;
_ISBN = isbn;
_Status = status;
_InventoryID = Guid.NewGuid();
}
#region Public Properties
[MessageBodyMember]
public Guid InventoryID
{
get { return _InventoryID; }
set { _InventoryID = value; }
}
[MessageBodyMember]
public String Title
{
get { return _Title; }
set { _Title = value; }
}
[MessageBodyMember]
public String Author|
{
get { return _Author; }
set { _Author = value; }
}

[MessageBodyMember]

public String ISBN
{
get { return _ISBN; }
set { _ISBN = value; }
}
[MessageBodyMember]
public String status
{
get { return _Status; }
set { _Status = value; }
}
#endregion Public Properties
}
[MessageContract(IsWrapped = false)]
public class BookInfoList
{
private List<binfo> _BookList;
public BookInfoList()
{
_BookList = new List<binfo>();
}
[MessageBodyMember]
public List<binfo> BookList
{
get { return _BookList; }
}
}
}

Step 3 : Now we press F6 and Build the solution.

Step 4 : Open the Service1.xamlx File.

Select ReciveRequest activity.
Right-click->Properties.
Select ServiceContract Property.
Change IService and OperationName.

Step 5 : Go to Variables Control from Workflow Designer.

Define the Varriable.
Varriable->Name->Varriable Type->Scope.

Step 6 : Go to ReciveRequest activity.

Content ->View message.
Define Message Data and Message Type.

Step 7 : Now we Press F5 then see WCF Test Client template open.

Step 8 : Double-click in Lookup option then give all information about the application data.

Step 9 : Go to Solution Explorer and Right-Click.

Select Add->New Item->Code Activity.
Write the below code.

Code :

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Activities;
namespace book
{
public sealed class lookup : CodeActivity
{
public InArgument<bookSearch> Search { get; set; }
public OutArgument<BookInfoList> BookList { get; set; }
public InArgument<string> Text { get; set; }
// If your activity returns a value, derive from CodeActivity<TResult>
// and return the value from the Execute method.
protected override void Execute(CodeActivityContext context)
{
string author = Search.Get(context).Author;
string title = Search.Get(context).Title;
string isbn = Search.Get(context).ISBN;
BookInfoList l = new BookInfoList();
l.BookList.Add(new binfo(title, author, isbn, "Available"));
l.BookList.Add(new binfo(title, author, isbn, "CheckedOut"));
l.BookList.Add(new binfo(title, author, isbn, "Missing"));
l.BookList.Add(new binfo(title, author, isbn, "Available"));
BookList.Set(context, l);
string text = context.GetValue(this.Text);
}
}
}

Step 10 : Drag the lookup activity from Toolbox.

Step 11 : Go to the lookup activity property and change the value.

Step 12 : Press F5 and run the application.