计算属性默认只有 getter ，必须在计算属性里加上setter，否则修改计算属性的值就会报错

computed: {
  uploadImages() {
    get: function () {
      return this.$store.getters.refundImages
    },
    set: function (newValue) {
      this.$store.state.refundImages= newValue
    }
  }
}