什么才算好样式的事件定义：

What is considered better style for an event definition:

public event Action<object, double> OnNumberChanged;

或

public delegate void DNumberChanged(object sender, double number);
public event DNumberChanged OnNumberChanged;

第一时间不打字，但委托人给名称的参数。当我键入​​此，我觉得2号是赢家，但我可能是错的。

The first takes less typing, but the delegate one gives names to the parameters. As I type this, I think number 2 is the winner, but I could be wrong.

编辑：不同的（第三个）的做法是赢家。阅读下文。

A different (third) approach is the winner. Read below.

推荐答案

无论是1或2。第三个选项是赢家

Neither 1 or 2. A third option is the winner

public event EventHandler<NumberChangedEventArgs> NumberChanged;

你打破了一些风格指南开发在C＃中，如使用类型事件参数不扩展EventArgs的。

You're breaking a number of style guidelines for developing in C#, such as using a type for event args that doesn't extend EventArgs.

是的，你能做到这样，因为编译器不关心。然而，人们阅读你的code会做跆拳道。

Yes, you can do it this way, as the compiler doesn't care. However, people reading your code will do a WTF.