What's the difference between "btn.Click += new RoutedEventHandler (ButtonClick)" and "btn.Click += ButtonClick"? [duplicate]

Question

In C#, when registering a event handler, you have two options (btn is of type System.Windows.Controls.Button):

btn.Click += new RoutedEventHandler (ButtonClick) and

btn.Click += ButtonClick.

What's the semantic difference between them and their implications?

Answer 1

The first version will compile without errors on all versions of .Net.

The second version will only compile on .Net 2 or later.

And that's the only difference. The second version is just some syntactic sugar introduced with .Net 2.

It's known as Method Group Conversion. See here for details:

http://mike-ward.net/blog/post/00020/anonymous-methods-method-group-conversions-and-eventhandler

Answer 2

As I understood it, nothing, the compiler will infer the delegate type and wrap it for you automatically, it's just a shorthand way of doing it (because who really wants to type it all out).