Fault Contract Exception in WCF Hosted on
Web App
Today, in this article let's try to study and
implement this interesting concept. It enables to show a friendly message to
user when unexpected values are inputted. It works great. So, we all are
good to go and implement this wonderful concept.
Question Arises: What is Fault
Contract?
Let's understand this Definition according to
scenario wise:
Think for the scenario the client makes some request to WCF Service and WCF
Service overlooks at the received request from client. So while processing the
request based on user inputted values, in some cases there might be chance of
occurrence of errors on service for incorrect inputted values by client. So when
the service sends some exception to client, it is not effectively received. So
WCF Service provides an effective way of delivering the error message to the
client by the usage of FAULT CONTRACT. So, if we implement this we can get a
better idea on this:
So, let's get ready to implement this very
useful concept.
The Complete Code of IService1.cs looks like
this:
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Runtime.Serialization;
using
System.ServiceModel;
using
System.ServiceModel.Web;
using
System.Text;
namespace
FaultContractException
{
// NOTE: You can use the "Rename"
command on the "Refactor" menu to change the interface name "IService1" in both
code and config file together.
[ServiceContract]
public interface
IService1
{ [OperationContract]
[FaultContract(typeof(Arthimetic))]
double add(double
a, double b);
}
}
The Complete Code of Service1.svc looks like this:
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.Runtime.Serialization;
using
System.ServiceModel; using
System.ServiceModel.Web;
using
System.Text;
using
System.Threading;
namespace
FaultContractException
{
// NOTE: You can use the "Rename"
command on the "Refactor" menu to change the class name "Service1" in code, svc
and config file together.
public class
Service1 : IService1
{
public double
add(double a, double
b)
{
try {
if (b == 0) { var
objArthimetic = new Arthimetic();
objArthimetic.Exception = "Fault Contract Exception";
objArthimetic.MethodName = "Add";
throw new
FaultException<Arthimetic>(objArthimetic,
"<b><i>Cannot Divide by zero");
}
}
catch (DivideByZeroException)
{ } return a/b;
}
}
}
The Complete Code of
Web.Config looks like this:
<?xml
version="1.0"?>
<configuration>
<system.web>
<compilation
debug="true"
targetFramework="4.0"
/>
</system.web>
<system.serviceModel>
<behaviors>
<serviceBehaviors>
<behavior>
<!--
To avoid disclosing metadata information, set the value below to false and
remove the metadata endpoint above before deployment
-->
<serviceMetadata
httpGetEnabled="true"/>
<!--
To receive exception details in faults for debugging purposes, set the value
below to true. Set to false before deployment to avoid disclosing exception
information
-->
<serviceDebug
includeExceptionDetailInFaults="false"/>
</behavior>
</serviceBehaviors>
</behaviors>
<serviceHostingEnvironment
multipleSiteBindingsEnabled="true"
/>
</system.serviceModel>
<system.webServer>
<modules
runAllManagedModulesForAllRequests="true"/>
</system.webServer>
</configuration>
The Complete Code of
WebForm1.aspx looks like this:
<%@
Page Language="C#"
AutoEventWireup="true"
CodeBehind="WebForm1.aspx.cs"
Inherits="Fault.WebForm1"
%>
<!DOCTYPE
html PUBLIC
"-//W3C//DTD XHTML 1.0 Transitional//EN"
"http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html
xmlns="http://www.w3.org/1999/xhtml">
<head
id="Head1" runat="server">
<title></title>
</head>
<body>
<form
id="form1"
runat="server">
<div>
<asp:ScriptManager
ID="ScriptManager1"
runat="server">
</asp:ScriptManager>
<asp:UpdatePanel
ID="UpdatePanel1"
runat="server">
<ContentTemplate>
<center>
<table>
<tr>
<td>
<asp:Label
ID="Label1"
runat="server"
Text="Please Enter First
Number" Font-Bold="true"
Font-Italic="true"
Font-Size="Larger"
ForeColor="Brown"></asp:Label>
</td>
<td>
<asp:TextBox
ID="TextBox1"
runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
<asp:Label
ID="Label2"
runat="server"
Text="Please Enter
Second Number" Font-Bold="true"
Font-Italic="true"
Font-Size="Larger"
ForeColor="Brown"></asp:Label>
</td>
<td>
<asp:TextBox
ID="TextBox2"
runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td>
</td>
<td>
<asp:Button
ID="Button1"
runat="server"
Text="Click Here"
BackColor="CadetBlue"
OnClick="Button1_Click"
/>
</td>
</tr>
</table>
<table>
<tr>
<td>
</td>
<td>
<asp:Label
ID="Label3"
runat="server"
Visible="false"
ForeColor="Brown"
Font-Size="Large"></asp:Label>
</td>
</tr>
</table>
</center>
</ContentTemplate>
</asp:UpdatePanel>
</div>
</form>
</body>
</html>
The Complete Code of
WebForm1.aspx.cs looks like this:
using
System;
using
System.Collections.Generic;
using
System.Linq;
using
System.ServiceModel;
using
System.Web;
using
System.Web.UI;
using
System.Web.UI.WebControls;
using
Fault.ServiceReference1;
namespace
Fault
{
public partial
class WebForm1 : System.Web.UI.Page
{
protected void
Page_Load(object sender,
EventArgs e)
{
}
protected void
Button1_Click(object sender,
EventArgs e)
{
try
{
if (TextBox1.Text ==
"" || TextBox2.Text == "")
{
Label3.Text = "<center><b><i>Please Enter Data";
Label3.Visible = true;
}
else
{
var objClient = new
Service1Client();
Label3.Text = ("<center> The Result of the Values is
<b>" + objClient.add(Convert.ToDouble(TextBox1.Text),
Convert.ToDouble(TextBox2.Text)) +
"</b></center>");
Label3.Visible = true;
TextBox1.Text = "";
TextBox2.Text = "";
}
}
catch (FaultException<Arthimetic>
exception)
{
Label3.Text =
("<center>FaultException<Arthimetic>: Arthimetic
fault while doing " + exception.Message);
Label3.Visible
= true;
}
}
}
}
The Output of the Application
looks like this:
![fig 1.gif]()
The Output of the Application
When Fault Contract Exception Arises looks like this:
![fig 2.gif]()
The Nothing Entered Values Output looks like this:
![fig 3.gif]()
I hope this article is useful for you. I look
forward for your comments and feedback.