What is Fault Contract?

what is FaultContract?

Fault Contract is used to expose an exception to client in friendly manner. why because exceptions are not belogs a  technology specific. so .net exceptions are technology specific(.net) these exceptions are not aware of other platforms. so to expose these .net  exceptions to clients of other technologies.(soa specifics: exceptions should be universal understand format). so wcf provides Faultcontract to expose about exceptions in wcf.

In WSDL we have a tag is <FaultTo> xml element exposes this exceptions to clients.

Fault Contract Demo

namespace FaultServiceDemo

{

     public class Service1 : IService1

    {

        SqlConnection con = new SqlConnection("uid=sa;pwd=zolt123$;database=wcfdb");

        SqlDataAdapter da;

        DataSet ds;

        #region IService1 Members

        public Employee Getdata(int EmpId)

        {

          

            da = new SqlDataAdapter("select * from emp where eid=" + EmpId, con);

            ds = new DataSet();

            da.Fill(ds);

            if (ds.Tables[0].Rows.Count == 0)

            {

                //create an object for the custom SOAP Fault.

                //and initialize the falut with our own customized fault message.

 CustomFaultMsg custmErr = new CustomFaultMsg { MyCustomErrMsg = "There is no employee exist with the emp id : " + EmpId };

                //Raise the customized fault message exception to the client.

                throw new FaultException<CustomFaultMsg>(custmErr);

            }

          // if the Emp record is exist , we have to return the emp Details....

            else

            {

                // Create an employee object and store all the emp record details in to the

                // employee object.

                Employee eobj = new Employee();

                eobj.Ename = ds.Tables[0].Rows[0][1].ToString();

                eobj.Eloc = ds.Tables[0].Rows[0][2].ToString();

                eobj.Deptid = Convert.ToInt32(ds.Tables[0].Rows[0][3].ToString());

                //   eobj.Uploadstatus = Convert.ToBoolean(ds.Tables[0].Rows[0][4].ToString());

                return eobj;

            }

        }

    }

}

At Client

            using (Service1Client proxy = new Service1Client())

            {

            

                string empid = Console.ReadLine();

                int eid = Convert.ToInt32(empid);

                try

                {

                    Employee emp = proxy.Getdata(eid);

                    Console.Write(emp.Ename);

                }

                catch (FaultException<CustomFaultMsg> faultMsg)

                {

                    // CustomFaultMsg obj = new CustomFaultMsg();

                    string error = faultMsg.Detail.MyCustomErrMsg;

                    Console.WriteLine(error);

                    Console.WriteLine(proxy.State);

                    //proxy.Close();

                    proxy.Abort();

                    Console.WriteLine(proxy.State);

                }

                catch (FaultException<CommunicationException> cex)

                {

                    string str=cex.Detail.Message;

                    Console.WriteLine(str);

               

                }                             

            }

            Console.Read();