应用程序升级如何在iPhone中运行
问题描述：
我打算在iTunes Store中发布iPhone应用程序。很快我会为它提供升级。但后来到现在的版本。我想知道升级系统在iPhone中是如何工作的。就像它取代整个应用程序并重新安装它删除以前的数据库一样，或者添加新版本保存数据库并且都是相同的。
I am planning to post an application for iPhone in iTunes Store. Soon I am gonna provide an upgrade for it. But later to current version. I want to know how the upgrade system works in iPhone. Like does it replaces the whole application and reinstall it deleteing the previous database or it adds the new version keeping the database and all the same.
答
升级会替换应用程序包，但沙箱中的任何其他内容（如文档文件夹，缓存，首选项等）都会保留在原位。
Upgrades replace the app bundle, but anything else in your sandbox (like the Documents folder, caches, preferences, etc) are preserved in place.