Handle exceptions in web services with Elmah

ASP.NET web services never fire Application_Error event and exceptions cannot be handled globally by ELMAH like in ASP.NET apps. But we can "manually" log exceptions using ELMAH:

public int WebServiceMethod() {  try {   ...  }  catch (Exception ex) {    Elmah.ErrorLog.GetDefault(      HttpContext.Current).Log(new Elmah.Error(ex, HttpContext.Current));  }}

You can use a SoapExtension to do this :

using System;using System.Web.Services.Protocols;namespace MyNamespace{    class ELMAHExtension : SoapExtension    {        public override object GetInitializer(Type serviceType)        { return null; }        public override object GetInitializer(LogicalMethodInfo methodInfo, SoapExtensionAttribute attribute)        { return null; }        public override void Initialize(object initializer)        { }        public override void ProcessMessage(SoapMessage message)        {            if (message.Stage == SoapMessageStage.AfterSerialize &&                message.Exception != null)            {                // Log exception here            }        }    }}

You register this in the web.config with the following lines :

<system.web>  <webServices>    <soapExtensionTypes>      <add type="MyNamespace.ELMAHExtension, MyDLL" priority="1" group="1" />    </soapExtensionTypes>  </webServices></system.web>

This will give you access to the HttpContext and SoapMessage objects which should give you all of the details you need about what was being called. I think the exception you retrieve at this stage will always be a SoapException and that the bit you are interested in is probably the inner exception.

You can use this code

 try{// your code in here}     catch (Exception ert)            {                Elmah.ErrorSignal.FromCurrentContext().Raise(ert);            }