问题描述
可能重复:
添加有缺点吗事件声明上的匿名空委托?
为事件定义一个空的委托主体，这样您就不必担心引发没有事件处理程序的事件，这是一种好习惯吗?(无需检查事件是否为空).
Is it a good practice to define an empty delegate body for a event so that you do not need to worry raise a event which have no event handler? ( no need to check whether event is null).
如下代码:
public event EventHandler<LoadEventArgs> LoadedData = delegate { };
推荐答案
我确实发现它很有用，是的.会有非常小的性能成本 - 但不必执行无效测试的可读性优势使其值得 IMO.
I've certainly found it useful, yes. There will be a tiny, tiny performance cost - but the benefit in readability for not having to perform the nullity test makes it worth it IMO.
值得指出的是，这是少数使用匿名方法而不是 lambda 表达式更好的情况之一 - 否则您必须命名将要忽略的参数，如下所示:
It's worth pointing out that this is one of the few times when it's good to use an anonymous method rather than a lambda expression - otherwise you have to name the parameters that you're going to ignore, like this:
public event EventHandler<LoadEventArgs> LoadedData = (sender, args) => {};
我不喜欢为我不打算使用的东西命名:)
I don't like having to name things I'm not intending to use :)
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