诀窍1：使用el.contains(e) 来判断点击的区域
诀窍2：使用mouseup
诀窍3：完成之后，移除事件
showpopover (e) {
this.popover = !this.popover
var closePopover = (event) => {
if (!this.$refs.popover.contains(event.target)) {
this.popover = false
document.body.removeEventListener('mouseup', closePopover)
}
}
document.body.addEventListener('mouseup',closePopover)
}