是否在“null”引用（即没有订阅者的事件）上调用扩展方法？

Evil or not evil?

邪恶与否?

public static void Raise(this EventHandler handler, object sender, EventArgs args)
{
   if (handler != null)
   {
      handler(sender, args);
   }
}

// Usage:
MyButtonClicked.Raise(this, EventArgs.Empty);

// This works too! Evil?
EventHandler handler = null;
handler.Raise(this, EVentArgs.Empty);
public static void