Exception Handling Advice for ASP.NET Web Applications

Exception Handling Advice for ASP.NET Web Applications

First Things First: Create a Custom Error Page
Whenever an unhandled exception occurs, the ASP.NET runtime displays its configured error page. (An unhandled exception is an exception that is not caught and handled by some method in the call stack when the exception is raised. If no method in the call stack catches the exception then it percolates all the way up to the ASP.NET runtime, which then displays the error page.)

The error page displayed by the ASP.NET runtime depends on two factors:

• Whether the website is being visited locally or remotely, and
• The configuration in Web.config.

ASP.NET's default error page is affectionately referred to as the Yellow Screen of Death. The screen shot on the right shows the default Yellow Screen of Death error page shown when an unhandled exception occurs for a remote visitor. When visiting locally, the Yellow Screen of Death page includes additional information about the exception that was raised.

While the Yellow Screen of Death error page is acceptable in the development environment, displaying such an error page in production to real users smacks of an unprofessional website. Instead, your ASP.NET application should use a custom error page. A custom error page is a user-friendly error page that you create in your project. Unlike the Yellow Screen of Death error page, a custom error page can match the look and feel of your existing website and explain to the user that there was a problem and provide suggestions or steps for the user to take.