Easy way to implement universal error handling in ASP.Net application

Folks,

I have an application that is primarily one page with a lot of user controls and custom controls. ASP.Net WebParts are being used. There is almost no code in the web page and its master page: it's all in various components.

The design requirements include an error message display panel. The client would like the app to display any errors occurring in any part of the app on the error message display rather than going to a custom error page. (This was a recent decision: when we started we were thinking custom error page.)

As far as I can tell, WebParts开发者_如何转开发 don't provide any default error handling (no capture of errors and displaying of messages) and user controls don't necessarily fire their OnError event when an internal error occurs.

So I'm looking at wrapping absolutely everything in Try ... Catch blocks, at least at the presentation level, and doing the handling. So my question is: is there any easy way to implement a kind of global, or at least class-wide, error handler, that will handle an error in the way I choose, interrupt the routine that was executing, but return (after handling) to the caller of the method that failed?

I'm willing to adapt code to verify that subroutines did what they were supposed to and returned appropriate values (ex: non-null data objects.) What I don't want is for the whole process to be aborted up to the very top, with rendering skipped, or (of course) the famous yellow and white screen.

I guess this is a case for aspect-oriented programming, but I don't think ASP.Net provides anything like that yet. I didn't get the impression that EntLib 5.0 did, either.

I would adore it if it were possible to decorate a method with an attribute that meant "On error call such-and-such a static method of such-and-such a class". But I doubt it is, yet.

Any suggestions are welcome.

Thanks,

Ann L.

For starters, it's bad practice to put Try Catch handlers around every piece of code in your application. There is a slight performance hit every time you set that up, and this could slow things down really fast.

In your Global.asax.cs (or .vb) file, there is a method in there called Application_Error which is the global error handler. This will catch any error you haven't previously caught (or thrown up) within the application.

You could easily put your error handling code here. It could be as simple as dumping the error message to a log for future review, or check for the exception type (SQL vs. File vs. HTTP) and do the error handling task related to the type.

You need to take a look at elmah. If you google 'elmah' it has an error module/handler that does pretty much what you are looking for (although it will take some extra tweaking..)

You might want to consider letting your errors 'bubble up' though.. There are some serious performance issues with writing a bunch of Try..Catch..Finally blocks...