1子组件

成功

  ChangeRest(event, file){/*   console.log(event)console.log(file)*//* console.log(URL.createObjectURL(file.raw))*/this.imageUrl = URL.createObjectURL(file.raw);/* this.imageUrl=event.tmp_urlconsole.log(this.imageUrl)*/console.log(1)this.eventSave=eventconsole.log(this.eventSave)this.$emit("ChangeLest",this.eventSave)},

2父组件

 changeRest1(val){console.log(2)console.log(val)this.preview=val.tmp_urlconsole.log(this.preview)this.form.thumbnail=val.relativepath+val.name}

3预览效果

通过两个不同的值实现预览 下面做个预览 库里面加个字段即可