Whenever we write a program we should expect the unexpected and add appropriate code to handle those exceptions.When we write a windows based application we use try/catch blocks in our methods to catch exceptions, and also we show a user friendly message in UI.
But when we work with WCF Service, It is not that much straight forward, So
- How do we handle exceptions in WCF Service?
- How to propagate a user-friendly error message to the client, who consumes the WCF Service?
- How to send business rule validation messages to WCF client?
Handling exceptions in WCF Service is different than usual exceptions in .NET. As the WCF clients may not be based on .NET Technologies we cannot utilize the .NET Exception object to exchange exception details over the wire. For this purpose we should have a generic way to pass exception details to all type of clients, who consumes WCF Service.
For this reason we have SOAP faults, SOAP faults are the way to propagate the exceptions from the service to the client application. .Net has FaultException<T> generic class which can raise SoapFault exception. Service should throw FaultException<T> instead of usual CLR Exception object. T can be any type which can be serialized.