iOS SDK分片上传错误，code400

error = Error Domain=com.aliyun.oss.serverError Code=-400 "(null)" UserInfo={__name=Error, HostId=XXXX.img-cn-hangzhou.aliyuncs.com, ErrorDetail=current PartNumber 2, you given part number 1is not in ascending order, Message=The list of parts was not in ascending order. Parts list must specified in order by part number., Code=InvalidPartOrder, RequestId=599E46B5529A00FF3EC73B48


我的操作是，分片上传一个图片到阿里云，然后继续上传同一张图片，之后会遇到这个错误，看起来是服务器错误？
初始化的时候会有一个uploadId，是根据这个来上传的哦