如何控制触发事件处理程序的顺序？ [英] How can I control the order in which event handlers are fired?

问题描述

事件处理程序是否按照附加到事件的顺序启动？如果没有，我可以对事件处理程序执行某种顺序，以便按照特定的顺序进行调用？

Are event handlers fired in the order that they attached to the event? If not, can I enforce some kind of order onto the event handlers such that they are called in a specific order?

推荐答案

假设事件的简单实现（在委托字段上使用+ =和 - =，然后使用 Delegate.Combine / Remove ）然后是，事件处理程序将按照订阅的顺序调用。该保证在 Delegate.Combine 文档：

Assuming a simple implementation of the event (using += and -= on a delegate field, which in turn will use Delegate.Combine/Remove) then yes, the event handlers will be called in the order in which they're subscribed. The guarantee is effectively given in the Delegate.Combine documentation:

返回值

新的多播（可组合）委托
与调用列表
连接 a
和 b

A new multicast (combinable) delegate with an invocation list that concatenates the invocation lists of a and b in that order.

查看我的关于事件的文章的一些示例，其中 Delegate.Combine / Remove do（以及什么事件在封面下） 。

See my article about events for some examples of which Delegate.Combine/Remove do (and what events are like under the covers).

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