AngularJS 中的 $evalAsync 和 $timeout 有什么区别? [英] What's the difference between $evalAsync and $timeout in AngularJS?

问题描述

我已经使用 AngularJS 一段时间了，发现需要使用 $timeout 每隔一段时间(似乎通常是初始化一个 jQuery 插件).

I've been using AngularJS for a little while now, and have found the need to use $timeout every once in a while (Seems to usually be to init a jQuery plugin).

最近，我一直在尝试对摘要循环有更好更深入的了解，我遇到了 $evalAsync 函数.

Recently, I've been trying to get a better and more in-depth understanding of the digest cycle, and I came across $evalAsync function.

似乎该函数产生的结果与 $timeout 类似，只是您不给它延迟.每次我使用 $timeout 时，它的延迟都是 0，所以现在我想知道我是否应该使用 $evalAsync 代替.

It seems like that function produces similar results to $timeout, only you don't give it delay. Every time I've used $timeout it has been with a delay of 0, so now I'm wondering if I should have used $evalAsync instead.

两者之间有什么根本区别吗?您会在哪些情况下使用其中一种?我想更好地了解何时使用哪个.

Are there any fundamental differences between the two? What cases would you use one over the other? I'd like to get a better feeling of when to use which one.

推荐答案

我最近在这里回答了这个问题:https://stackoverflow.com/a/17239084/215945(该答案链接到与 Misko 的一些 github 交流.)

I recently answered essentially this question here: https://stackoverflow.com/a/17239084/215945 (That answer links to some github exchanges with Misko.)

总结:

• 如果代码使用指令中的$evalAsync 排队，它应该在 DOM 被 Angular 操作之后运行，但之前浏览器渲染
• 如果代码使用控制器中的 $evalAsync 进行排队，它应该在 DOM 被 Angular 操作之前运行(并且在浏览器呈现之前)——很少这样做你想要这个
• 如果代码使用 $timeout 排队，它应该在 DOM 被 Angular 操作之后运行，并且在浏览器呈现(在某些情况下可能会导致闪烁)

• if code is queued using $evalAsync from a directive, it should run after the DOM has been manipulated by Angular, but before the browser renders
• if code is queued using $evalAsync from a controller, it should run before the DOM has been manipulated by Angular (and before the browser renders) -- rarely do you want this
• if code is queued using $timeout, it should run after the DOM has been manipulated by Angular, and after the browser renders (which may cause flicker in some cases)

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