EventHandler类型，没有事件args [英] EventHandler type with no event args

问题描述

当我们要将数据传递给事件订阅者时，我们使用EventArgs（或CustomEventArgs）。

When we want to pass data to an event subscriber, we use EventArgs (or CustomEventArgs) for this.

.Net提供了一个类型为EventHandler的构建，它使用一个参数，也是构建的EventArgs类的一个实例。

.Net provides a build in type EventHandler that uses as a parameter an instance of EventArgs class that is build in as well.

当我需要通知用户某些操作已经结束的情况下，例如搜索是过度？我不想使用EventArgs，它不会包含任何东西。

What about cases, when I need to notify a subscriber that some action is over, for example search is over? I don't want to even use EventArgs, that won't contain anything.

是否有一个类型用于发信号通知另一个类，而不需要使用空的EventArgs？

Is there a build in type for signaling another class, without the need to use empty EventArgs?

推荐答案

你可以做几件事：

1. 使用EventHandler和基本的EventArg类 - 确定它是空的，但是这是否受到伤害？


2. 使用自己的代理，并使用事件MyDelegateWithoutParams MyEvent;


3. 使用具有IObservable的观察者模式


4. 让客户端通过一个Action，并调用此操作

1. youse your normal event with EventHandler and the basic EventArg class - sure it's empty but does this hurt?
2. make your own delegate and use this with event MyDelegateWithoutParams MyEvent;
3. use the Observer-Pattern with IObservable instead
4. let the clients pass a Action do you and call this action

我希望其中一个选择是您的喜好。我使用1和4这种情况（4个主要是只有一个听众。

I hope one of this options is to your liking. I use 1 and 4 for this kind of situation (4 mostly if there will be only one "listener".

PS：我猜2不符合<一个href =http://msdn.microsoft.com/de-de/library/w369ty8x.aspx =noreferrer> .net框架指南，所以也许这不是最好的主意;）

PS: I guess 2 won't conform to the .net framework guidelines so maybe this is not the best idea ;)

这篇关于EventHandler类型，没有事件args的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！