Using the .NET Exception Class

The base class that all exceptions inherit from is the Exception class. The Exception class has the properties described in Table 4-1.

Table 4-1: Exception Properties

Property	Description
HelpLink	The link to the help file associated with the error
InnerException	The exception that caused the current exception
Message	The error message
Source	The application that caused the error
StackTrace	Call stack up to the point where the error was thrown
TargetSite	The method that threw the current exception

The Exception class supports several other properties and methods, but those in Table 4-1 are the only ones you need to be concerned with in this chapter. There are two classes that inherit from this base Exception class that are of interest to you as well. These are the ApplicationException class and the SystemException class. The ApplicationException class is the base class from which almost all application exceptions inherit. You should use this class to indicate that an application caused the errors. The operating system or Common Language Runtime (CLR) uses the SystemException class to inform an application that the system threw an error. The MSDN documentation recommends that applications do not throw or handle SystemException errors. The only difference between these classes is an initial numeric value.

Note

Other Exception classes inherit directly from the Exception class, but you should not be concerned with these for this chapter. For more information, search for "Exception Hierarchy" in the MSDN documentation.

The ApplicationException class is the class that you will inherit from for your custom application errors.