Exception Handling in WCF using Fault Contract

Anand Thakur

7y302k7100Article

7 Comments

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kalu singh rao10y ago
Nice...
neelesh gour16y ago
very nice explain and easily expained..thanks c-sharpcorner
Chiranjib Chowdhury17y agoedited
Hi, This is really a good article for beginners. But one important thing is missing in it. If somebody try to run the sample application he may get the error "System.ServiceModel.FaultException`1 was unhandled by user code". If somebody experiences this, he need to change debugging settings of his "VS Environment". Those are as follows: 1. Uncheck "Enable Exception Assistant" 2. Uncheck "Enable just My Code (Managed Only)" To do this go to Tools -> options -> Debugging -> General. For more information consult the following link: http://sergecalderara.wordpress.com/2008/11/25/systemservicemodelfaultexception1-was-unhandled-by-user-code/
- Vishal16y ago
  Perform below steps 1) Host the Web service on IIS 2) Delete the previous Service reference from the client 3) Add new service reference using the IIS hosted path. try this & it will work
sachin mhatre17y ago
This helps
Firoz Basser18y ago
Nice and simple solution. Works for me! Can one retrieve the method name/ module name when raising exceptions? This would be great for more advanced fault reporting.
- Anand Thakur18y ago
  Yes you can try to explore given code, Atleast you put informations here MyFaultException theFault = new MyFaultException(); theFault.Reason = "Some Error " + exp.Message.ToString(); throw new FaultException<MyFaultException>(theFault);

Introduction

In all managed applications, processing errors are represented by Exception objects. In WCF applications, service methods communicate processing error information using SOAP fault messages. SOAP faults are message types that are included in the metadata for a service operation and, therefore, create a fault contract that clients can use to make their operation more interactive. In addition, because SOAP faults are expressed to clients in XML form, they are highly interoperable.

Exception Handling in WCF using Fault Contract

To be more concrete, let us start with an example:

Create an empty solution in VS2005 called "IndigoException". Add one project called "IndigoService". Next add a reference to System.ServiceModel and then add an interface.

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
using System.Runtime.Serialization;
namespace Indigo
{
[ServiceContract()]
public interface IService
{
[OperationContract]
[FaultContract(typeof(MyFaultException))]
string GetMessage();
}
}

Add one more class as follows:

using System;
using System.Text;
using System.Runtime.Serialization;
namespace Indigo
{
[DataContract]
public class MyFaultException
{
private string _reason;
[DataMember]
public string Reason
{
get { return _reason; }
set { _reason = value; }
}
}
}

Add one class "Service" and a reference to System.ServiceModel

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
namespace Indigo {
public class Service: IService {
#
region IService Members
public string GetMessage() {
try
{
int i, j, k;
j = 1;
k = 0;
i = j / k;
} catch (Exception exp)
{
MyFaultException theFault = new MyFaultException();
theFault.Reason = "Some Error " + exp.Message.ToString();
throw new FaultException < MyFaultException > (theFault);
}
return "No Error";
}
# endregion
}
}

Build the project.

Now add another project "Host" and add reference to "IndigoService" project and to System.ServiceModel

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
namespace Indigo
{
class IndigoHost
{
internal static ServiceHost myServiceHost = null;
static void Main(string[] args)
{
StartService();
Console.WriteLine("Service at your service");
Console.ReadKey();
StopService();
}
internal static void StartService()
{
myServiceHost = new ServiceHost(typeof(Indigo.Service));
myServiceHost.Open();
}
internal static void StopService()
{
//Call StopService from your shutdown logic (i.e. dispose method)
if (myServiceHost.State != CommunicationState.Closed)
myServiceHost.Close();
}
}
}

Add app.config with the following XML:

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.serviceModel>
<services>
<service behaviorConfiguration="MyServiceTypeBehaviors" name="Indigo.Service">
<endpoint address="Service" binding="wsHttpBinding" contract="Indigo.IService" />
<host>
<baseAddresses>
<add baseAddress="http://localhost:1111/Indigo" />
</baseAddresses>
</host>
</service>
</services>
<behaviors>
<serviceBehaviors>
<behavior name="MyServiceTypeBehaviors">
<serviceMetadata httpGetEnabled="true" />
<serviceDebug includeExceptionDetailInFaults="true" />
</behavior>
</serviceBehaviors>
</behaviors>
</system.serviceModel>
</configuration>

Build the project.Run Host.exe from VS2005 command prompt. You should get the message at the command prompt as follows:

Add another project "IndigoClient" and add System.ServiceModel

Now add service refrence to the service URL (i.e. http://localhost:1111/Indigo)

It will create localhost.cs in service reference.

Add a class Program.cs as follows:

using System;
using System.Collections.Generic;
using System.Text;
using System.ServiceModel;
namespace Indigo
{
class Program
{
static void Main(string[] args)
{
string result = "";
try
{
IndigoClient.localhost.IService ww = new IndigoClient.localhost.ServiceClient();
result = ww.GetMessage();
}
catch (FaultException<IndigoClient.localhost.MyFaultException> ee)
{
result = "Exception: " + ee.Detail.Reason;
}
Console.WriteLine(result);
Console.ReadLine();
}
}
}

Add app.config with following XML

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
<system.serviceModel>
<bindings>
<wsHttpBinding>
<binding name="WSHttpBinding_IService" closeTimeout="00:01:00"
openTimeout="00:01:00" receiveTimeout="00:10:00" sendTimeout="00:01:00"
bypassProxyOnLocal="false" transactionFlow="false" hostNameComparisonMode="StrongWildcard"
maxBufferPoolSize="524288" maxReceivedMessageSize="65536"
messageEncoding="Text" textEncoding="utf-8" useDefaultWebProxy="true"
allowCookies="false">
<readerQuotas maxDepth="32" maxStringContentLength="8192" maxArrayLength="16384"
maxBytesPerRead="4096" maxNameTableCharCount="16384" />
<reliableSession ordered="true" inactivityTimeout="00:10:00"
enabled="false" />
<security mode="Message">
<transport clientCredentialType="Windows" proxyCredentialType="None"
realm="" />
<message clientCredentialType="Windows" negotiateServiceCredential="true"
algorithmSuite="Default" establishSecurityContext="true" />
</security>
</binding>
</wsHttpBinding>
</bindings>
<client>
<endpoint address="http://localhost:1111/Indigo/Service" binding="wsHttpBinding"
bindingConfiguration="WSHttpBinding_IService" contract="IndigoClient.localhost.IService"
name="WSHttpBinding_IService">
<identity>
<userPrincipalName value="[email protected]" />
</identity>
</endpoint>
</client>
</system.serviceModel>
</configuration>

Note: Please add your username and domain name under userPrincipalName

Now run the client project; you should get following error message:

You can now see the detailed error message returned from the service.