Capture WebService exceptions using soap extensions in ASP. NET

Application_error exceptions that cannot be caught

 
[Webmethod]Public StringHelloworld (){Throw NewException ("This exption can't be handled by application_error method");Return "Hello World";}
 

 
Defining application_error will not capture this exception.
 

 
The reason is that you need to know the lifecycle of the SOAP request in ASP. NET.
 

 

If the process message process calls webmethodSoapexception,SoapheaderexceptionAfter being serialized, return at the soap <fault> node.

Exceptions in the process message process are handled using the soap extended extension.
We can process soap extension.

Code 

   Public     Class  Soapexceptionhandler: system. Web. Services. Protocols. soapextension
{
  Public     Override     Void Processmessage (system. Web. Services. Protocols. soapmessage message)
{
  If  (Message. Stage  =  Soapmessagestage. afterserialize)
{
  If  (Message. Exception  ! =     Null )
{
Logutil. log. Error (message. Exception. innerexception );
}
}
}

  Public     Override     Object Getinitializer (type servicetype)
{
  Return     Null  ;
}

  Public     Override     Object Getinitializer (
Logicalmethodinfo methodinfo,
Soapextensionattribute)
{
  Return     Null  ;
}

  Public     Override    Void  Initialize (  Object  Initializer)
{
}
} 

 
Configure in the web. config system. Web Node
 

 Code 

     <  WebServices  > 
  <  Soapextensiontypes  >  
  <  Add  Type  = "Elplan. App. soapexceptionhandler, elplan. app"  Priority  = "1"  Group  = "High"    />  
  </  Soapextensiontypes  >  
  </  WebServices  > 

Debugging:

If you use vs to directly run and debug asmx, it is not possible (because it is not a complete SOAP request.) You can use webservicestudio.
Address: http://www.codeplex.com/WebserviceStudio

ReferenceArticle:

using soap extensions in ASP. Net
handling and throwing exceptions in XML Web Services
how to create a global exception handler for a Web Service