#902 – Data Available to the Handler of a Wrapped Exception

There are cases when you handle an exception by wrapping the original exception within a new exception that you then throw.  The original exception is wrapped by storing it in the InnerException property of the new exception.

When a handler further up catches the new exception, it will see the following:

• StackTrace property shows the calling sequence only down to the method that created the new exception (the handler that caught the lower-level exception)
• The original (wrapped) exception is accessible through the InnerException property

For example, suppose that:

• A Main method calls DoDogStuff method, which calls Dog.Bark method
• Dog.Bark throws a DogBarkException
• DoDogStuff catches DogBarkException, wraps the exception in an ApplicationException and throws the new exception

A handler in Main can then catch the ApplicationException and will see:

• StackTrace of wrapped exception shows – Main called DoDogStuff
• InnerException contains the original DogBarkException
• StackTrace of inner exception shows – DoDogStuff called Dog.Bark