上传AppStore报错ERROR ITMS-90725_error itms-90725: "sdk version issue. this app was

最近用xcode 8 上传到appstore 的时候，报了一个错误 上传AppStore会报错ERROR ITMS-90725："SDK Version Issue. This app was built with the iOS '10.0' SDK. All new iOS apps submitted to the App Store must be built with the iOS '11.0' SDK or later, included in Xcode [9.0] or later. Please update Xcode and rebuild your app."

解决方法：

（1）下载一个xcode 9 ，直接用xcode 9 打包

（2）下载xcode 9，显示报内容  通过以下路径去找ios '11.0'的sdk 

Contents/Developer/Platforms/iPhoneOS.platform/Developer/SDKs/iPhoneOS11.2.sdk 将最后这个文件拷贝到xcode 8 线面的相同路径下，把原有的 10点几的sdk 删除掉就可以上传成功了