1：选择框设置

2：在return中设置初始值

queryParam: {
          createTimeRange: []
        }

3：在方法中设置

 methods: {
      getQueryParams () {
        var param = Object.assign({}, this.queryParam, this.isorter)
        param.field = this.getQueryField()
        param.pageNo = this.ipagination.current
        param.pageSize = this.ipagination.pageSize
        delete param.createTimeRange // 时间参数不传递后台
        return filterObj(param)
      },
      onDateChange: function (value, dateString) {
        this.queryParam.createTime_begin = dateString[0]
        this.queryParam.createTime_end = dateString[1]
      },
      onDateOk (value) {
      }
    }