Adding Wcf Service Logging

you don't need to change your source code just add to your service web.config:

<system.diagnostics>
<sources>
<source name="System.ServiceModel"
                    switchValue="Information, ActivityTracing"
                    propagateActivity="true">
<listeners>
<add name="traceListener"
type="System.Diagnostics.XmlWriterTraceListener"
initializeData= "C:\Log\wcf.svclog" />
</listeners>
</source>
</sources>
</system.diagnostics>