<span ref="projectButton">
  <el-popover v-model="visible" trigger="manual" placement="bottom" @show="show" @hide="hide">
   <p>啦啦啦</p>
   <el-button slot="reference" type="primary" @click="visible = !visible">show</el-button>
  </el-popover>
</span>

data () {
 return {
  visible: false
 }
},
methods: {
 show () {
  document.addEventListener('click', this.hidePanel, false)
 },
 hide () {
  document.removeEventListener('click', this.hidePanel, false)
 },
 hidePanel (e) {
  if (!this.$refs.projectButton.contains(e.target)) {
   this.visible = false
   this.hide()
  }
 }
}

<template>
 <div>
 <div class="show" v-show="show" v-clickoutside="handleClose">
 显示
 </div>
 </div>
</template>
 
<script>
const clickoutside = {
 // 初始化指令
 bind(el, binding, vnode) {
  function documentHandler(e) {
   // 这里判断点击的元素是否是本身，是本身，则返回
   if (el.contains(e.target)) {
    return false;
 }
   // 判断指令中是否绑定了函数
   if (binding.expression) {
    // 如果绑定了函数 则调用那个函数，此处binding.value就是handleClose方法
    binding.value(e);
   }
 }
  // 给当前元素绑定个私有变量，方便在unbind中可以解除事件监听
  el.__vueClickOutside__ = documentHandler;
  document.addEventListener('click', documentHandler);
 },
 update() {},
 unbind(el, binding) {
  // 解除事件监听
  document.removeEventListener('click', el.__vueClickOutside__);
  delete el.__vueClickOutside__;
 },
};
export default {
 name: 'HelloWorld',
 data() {
  return {
   show: true,
  };
 },
 directives: {clickoutside},
 methods: {
  handleClose(e) {
   this.show = false;
  },
 },
};
</script>
 
<!-- Add "scoped" attribute to limit CSS to this component only -->
<style scoped>
.show {
 width: 100px;
 height: 100px;
 background-color: red;
}
</style>

<template>
 <div>
  <div class="mask" v-if="showModal" @click="showModal=false"></div>
  <div class="pop" v-if="showModal">
    <button @click="showModal=false" class="btn">点击出现弹框</button>
  </div>
  <button @click="showModal=true" class="btn">点击出现弹框</button>
 </div>
</template>

<script>
export default {
 data() {
  return {
   showModal: false
  };
 }
};
</script>

<style scoped>
.mask {
 background-color: #000;
 opacity: 0.3;
 position: fixed;
 top: 0;
 left: 0;
 width: 100%;
 height: 100%;
 z-index: 1
}
.pop {
 background-color: #fff;
 
 position: fixed;
 top: 100px;
 left: 300px;
 width: calc(100% - 600px);
 height:calc(100% - 200px);
 z-index: 2
}
.btn {
 background-color: #fff;
 border-radius: 4px;
 border: 1px solid blue;
 padding: 4px 12px;
}
</style>