Chapter 9 - Structured Error Handling

Here's what the Microsoft documentation says about it:

A Catch statement handles an exception that is of the same type as the type declared in the Catch statement, or of a type derived from it. If you supply a Catch statement that does not specify an exception type, it handles any exception derived from the Exception class.

A Catch statement, whether or not it specifies an exception type, can optionally include the When clause. When is followed by an expression that must be convertible to Boolean. The exception is handled only if it is of the right type and the When expression evaluates to True.

Translating, this says, "A Catch statement will handle the error in the As Exception clause unless the clause isn't there. Then the Catch statement will try to handle every exception. Therefore, if a When clause is used instead of As Exception, you have to be careful code the test correctly.

• Structure FINALLY comes to VB Error Handling!
• Exceptions to the Book! - A typo - And a more significant 'exception'
• Microsoft's Point of View
• The Difference in Code
• The Microsoft Way - Here's the Microsoft documentation method
• About the New Tricks
• What Could Go Wrong? - A Few Things That Might Be Confusing
• About the Error Messages
• Confusion in Disk Drive Error Handler ?
• Assignment For Next Time