ASP.NET in a Nutshell, 2nd Edition

Error Handling | 215

Error Handling

This is the Title of the Book, eMatter Edition

Copyright © 2008 O’Reilly & Associates, Inc. All rights reserved.

For the code in Example 10-4 to work, you need to provide valid email addresses

for the To and From properties of the MailMessage object instance.

If an unhandled exception occurs in a custom error page, no further redirect will

occur, so the user will see a blank page. This situation makes it extremely impor-

tant for you to ensure that no unhandled exceptions occur in custom error pages.

For example, it might be a good idea to wrap the call to SmtpMail.Send in

Example 10-4 in a

Try...Catch block) to handle potential problems with

connecting to the specified SMTP server. For more information about using the

Try...Catch block, see “Structured Exception Handling,” later in this chapter.

The advantage of using custom error pages is that it allows you to handle a lot of

errors from a single location (or a small number of locations). The disadvantage is

that there’s not much you can do to handle the error, other than display a helpful

message and notify someone that an error occurred. The reason for this is that you

don’t have access to the actual exception object in a custom error page, which

means you can neither display information about the specific exception nor take

steps to handle it.

Page_Error and Application_Error

Another technique for error handling ...