在Vue实例中手动侦听鼠标事件 [英] Manually listen for mouse event in Vue instance

问题描述

我正在尝试从子组件中侦听子组件中的鼠标事件，但没有触发该事件.当我用html侦听事件时它起作用，但是不起作用

I am trying to listen to a mouse event in a child component from the component, but I don't get the event being fired. It works when I listen for the event in html, but not

这如您所见:

Vue.config.devtools = false;
Vue.config.productionTip = false;

new Vue({
  el: '#mouse',
  data: {
    message: 'Hover Me!'
  },
  methods: {
    mouseover: function() {
      this.message = 'Good!'
    },
    mouseleave: function() {
      this.message = 'Hover Me!'
    }
  }
});

body {
  background: #333;
}

body #mouse {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: block;
  width: 280px;
  height: 50px;
  margin: 0 auto;
  line-height: 50px;
  text-align: center;
  color: #fff;
  background: #007db9;
}

body #mouse a {
  display: block;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js"></script>
<div id="mouse">
  <a @mouseover="mouseover" @mouseleave="mouseleave">
    {{message}}
  </a>
</div>

该事件不起作用，因为事件侦听是通过代码完成的.

This one doesn't work because the event listening is done in code.

Vue.config.devtools = false;
Vue.config.productionTip = false;

new Vue({
  el: '#mouse',
  data: {
    message: 'Hover Me!'
  },
  methods: {
    mouseover: function() {
      this.message = 'Good!'
    },
    mouseleave: function() {
      this.message = 'Hover Me!'
    },
    mounted() {
      this.$on('mouseleave', this.mouseleave);
    }
  }
});

body {
  background: #333;
}

body #mouse {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: block;
  width: 280px;
  height: 50px;
  margin: 0 auto;
  line-height: 50px;
  text-align: center;
  color: #fff;
  background: #007db9;
}

body #mouse a {
  display: block;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js"></script>
<div id="mouse">
  <a @mouseover="mouseover">
    {{message}}
  </a>
</div>

从组件本身而不是在html中手动侦听mouseleave事件的正确方法是什么?

What is the correct way of manually listening for mouseleave event from the component itself rather than in the html?

推荐答案

在第二个片段中，mounted钩子函数应该在方法之外，这不能解决问题，而函数用于自定义事件，而不用于诸如click和mouseleave之类的本机事件，如解释的 here :

In the second snippet the mounted hook function should be outside of methods, this will not solve the problem, and vm.$on function is used for custom event not for native ones like click and mouseleave, like explained here :

如果您这样称呼:

 vm.$on('test', function (msg) {
    console.log(msg)
  })

您应该在某处输入类似以下代码的代码:

You should have a code like the following one somewhere :

 vm.$emit('test', 'hi')

由于您无法使用this.$on方法，因此我建议您使用通过提供link或所需的任何内容，将ref属性添加到a元素中，从而在ref 中并在已挂接的挂钩中添加以下代码:

Since you're not able to use this.$on method, i recommend you the following solution using ref by adding ref attribute to your a element by giving link or whatever you want and in the mounted hook add the following code:

    this.$refs.link.addEventListener('mouseleave', () => {
      this.mouseleave()
    }, false);

Vue.config.devtools = false;
Vue.config.productionTip = false;

new Vue({
  el: '#mouse',
  data: {
    message: 'Hover Me!'
  },
  methods: {
    mouseover: function() {
      this.message = 'Good!'
    },
    mouseleave: function() {
      this.message = 'Hover Me!'
    }
  },
  mounted() {
    this.$refs.link.addEventListener('mouseleave', () => {
      this.mouseleave()
    }, false);

  }
});

body {
  background: #333;
}

body #mouse {
  position: absolute;
  top: 50%;
  left: 50%;
  transform: translate(-50%, -50%);
  display: block;
  width: 280px;
  height: 50px;
  margin: 0 auto;
  line-height: 50px;
  text-align: center;
  color: #fff;
  background: #007db9;
}

body #mouse a {
  display: block;
  width: 100%;
  height: 100%;
  cursor: pointer;
}

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js"></script>

<div id="mouse">
  <a @mouseover="mouseover" ref="link">
    {{message}}
  </a>
</div>

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