Apps using background location services must provide a reason that clarifies the purpose of the use
上架App Store被拒
原因：
Apps using background location services must provide a reason that clarifies the purpose of the use, using mechanisms described in the Human Interface Guidelines
Details
Your app uses background location services but does not clarify the purpose of its use in the location modal alert as required in the iOS Human Interface Guidelines.
We’ve attached screenshot(s) for your reference.
Next Steps
Please reconfigure the UIAlertControllerStyleAlert in your code and specify the intended purpose of using background location in its message field.
Resources
For additional information and instructions on configuring and presenting an alert, see the Accessing User Data section of the iOS Human Interface Guidelines and the UIKit Framework Reference.
翻译一下：
你的应用程序使用后台位置服务，但没有说明它在iOS人机界面指南中所使用的位置模式警告的用途
原来苹果在近期又修改了审核规则，需要在获取用户定位的时候，说明用户为什么需要获取用户的位置。
所以在工程 info.plist文件里面增加 Privacy - Location Always Usage Description 或 Privacy - Location When In Use Usage Description的时候需要配上详细说明文字但要简洁，告诉用户你为什么要访问他的位置！