ASP.NET 2.0 Cookbook, 2nd Edition

8.2. Handling Errors at the Page Level

Problem

You want to trap any error that occurs on a page and, using a page-level event handler, redirect the user to another page that displays the information about the problem.

Solution

Add code to the Page_Error event handler of the page to set the ErrorPage property of that page to the URL you want to display to the user when an error occurs.

In the code-behind for the page, use the .NET language of your choice to:

1. Add a Page_Error event handler.

2. In the event handler, get a reference to the last error that occurred using the GetLastError method.

3. Set the ErrorPage property of the Page object to the URL of the page you want displayed after the error, adding querystring parameters to pass error information to the page.

Examples 8-3 (VB) and 8-4 (C#) demonstrate this solution. (Because the .aspx file for this example contains nothing related to the error handling, it is not included here.)

Discussion

The Page_Error event of the ASP.NET Page object is raised any time an unhandled error occurs in a page. The first action required in the event handler is to get a reference to the last error. After getting the reference, the code should perform the required logging, notifications, etc. See Recipe 8.3 for an example of writing to the event log.

ASP.NET provides you with the ability to redirect the user to another page when an error occurs. To use this feature, set the ErrorPage property of the Page object to the URL of the page you want the user to see. You ...