Office® XP Development with VBA

Class Module Errors

Class modules are not immune to runtime errors, but the way you handle them is a bit different from standard modules. Also, you can define custom errors that represent other object occurrences that your application needs to react to.

In general, you do not want a class to handle its own errors directly. Instead, a class should report errors to the program that is using it, so that the program can handle the errors in a manner appropriate to the situation. This includes VBA's built-in errors, as well as error situations that are specific to your class, such as an inappropriate value being passed as a method argument.

To define custom errors, it is necessary to associate a number with each error. Clearly, you cannot use a number ...