新建click-outside.js文件

const clickoutsideContext = '@@clickoutsideContext'

export default {
  /*
   @param el 指令所绑定的元素
   @param binding {Object} 
   @param vnode vue编译生成的虚拟节点
   */
  bind(el, binding, vnode) {
    const documentHandler = function(e) {
      if (!vnode.context || el.contains(e.target)) {
        return false
      }
      if (binding.expression) {
        vnode.context[el[clickoutsideContext].methodName](e)
      } else {
        el[clickoutsideContext].bindingFn(e)
      }
    }
    el[clickoutsideContext] = {
      documentHandler,
      methodName: binding.expression,
      bindingFn: binding.value
    }
    setTimeout(() => {
      document.addEventListener('click', documentHandler)
    }, 0)
  },
  update(el, binding) {
    el[clickoutsideContext].methodName = binding.expression
    el[clickoutsideContext].bindingFn = binding.value
  },
  unbind(el) {
    document.removeEventListener(
      'click',
      el[clickoutsideContext].documentHandler
    )
  }
}

全局使用在main.js中引入,我这里是在assets/js文件中，引入时按照自己的路径引入

import clickOutside from '../../assets/js/click-outside'
Vue.directive('clickoutside', clickOutside)

页面使用，在弹框元素上添加v-clickoutside="事件名" 

在methods中写相应的逻辑