autoeventwireup performance cost

Question

I have been looking at improving my asp.net page performance, is it worth changing autoeventwireup from true to false and adding the event handlers or is the performance pen

Answer 1

The performance difference is negligible.

Answer 2

The performance is 0, because once wired up (once your application is compiled in memory), it never has to do it again. What I mean by that is, the ASP.NET framework isn't constantly itterating through every method by name to see if it should be wired up.

But, I strongly suggest you turn it off, because it usually causes issues of double page loads or whatever (if you wire up an event yourself, but due to naming it a certain way, ASP.NET wires it up too).

That's a feature that I wish was defaulted to off.

Answer 3

From MSDN article.

Performance Tips and Tricks in .NET Applications

Avoid the Autoeventwireup Feature

Instead of relying on autoeventwireup, override the events from Page. For example, instead of writing a Page_Load() method, try overloading the public void OnLoad() method. This allows the run time from having to do a CreateDelegate() for every page.

Knowledge Base article:

How to use the AutoEventWireup attribute in an ASP.NET Web Form by using Visual C# .NET

When to avoid setting the value of the AutoEventWireup attribute to true

If performance is a key consideration, do not set the value of the AutoEventWireup attribute to true. The AutoEventWireup attribute requires the ASP.NET page framework to make a call to the CreateDelegate function for every ASP.NET Web Form page. Instead of using automatic hookup, you must manually override the events from the page.

Answer 4

The wireup isn't done at compile-time. It's done at runtime. As described in this article:

http://odetocode.com/Blogs/scott/archive/2006/02/16/2914.aspx

There IS a performance penalty because of the calls to CreateDelegate which must be made every time a page has been created. The performance hit is probably negligible, but it does exist.