使用 vm.$on 监听 vue.js 2.0 中 child 发出的事件 [英] Use vm.$on to listen to event emitted from child in vue.js 2.0

问题描述

我已经阅读了 vue.js 事件部分的事件，但它似乎只给出了如何使用 html 中的 vm.$on 处理程序来侦听事件的示例.在这与 2.0 的新变化之间，我不确定如何简单地从 child -> parent 传输事件.

I've been through the vue.js events section on events but it seems to only give examples of how to listen to events using the vm.$on handler within html. Between that and the new changes for 2.0 I'm unsure how to simply transmit a event from child -> parent.

我需要传输一个事件，因为在父母收到后我想将它广播给另一个孩子.

I need to transmit an event because after parent receiving i want to broadcast it to another child.

我使用的是单页组件，这是我的设置:

I'm using single page components, this is my setup:

// parent
export default {
  mounted: function () {
    this.$on('myEvent', function (msg) {
    console.log('caught in parent', msg)
  });
 },
 components: {
  'child': child,
 },
}

// child
this.$emit('myEvent', true)

请问如何在父虚拟机上接收此事件?注意，我不想在 html 中使用 $on.我希望 vm 中的事件接收逻辑应该在那里.

How can I receive this event on the parent vm please? Note, I don't want to use $on in the html. I want the event receiving logic in the vm where it should be.

谢谢，

推荐答案

Vues 关于 $emit 的文档不是很全面，但是有一些方法可以做到这个.首先，如果你想使用 this.$on()，你必须在你想要发送消息的 vue 模型上 $emit，所以如果你从一个您可以使用以下方法发送给直接父级的组件:

Vues documentation on $emit is not very comprehensive, however, there are a few ways to do this. Firstly you have to $emit on the vue model you want to send the message to if you want to use this.$on(), so if you are sending from a component you can emit to the direct parent using:

this.$parent.$emit('myEvent',true);

但是，如果您有很长的父链，这可能会成为问题，因为您必须在子链上$emit，因此在这种情况下，您可以使用 Vue 实例作为总线:

However, this can become problematic if you have a long chain of parents because you have to $emit up the child chain, so in that case you can use a Vue instance as a bus:

// In the root as a global variable so all components have access
var bus = new Vue({});

或者如果您使用的是单文件组件.

Or if you are using single file components.

window.bus = new Vue({});

然后在接收器中:

bus.$on('myEvent',() => {
   // Do stuff
});

在发射器中:

bus.$emit('myEvent',true);

最后，如果你发现 app 对于一个简单的总线来说太复杂了，那么你可以使用 vuex:

Finally, if you find you app getting too complex for a simple bus then you can use vuex:

https://vuex.vuejs.org/en/index.html

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