mobile - 对于移动应用程序更新，为什么需要重新下载整个应用程序？

Question

我注意到在许多平台上:iOS、Android 和黑莓，当更新应用程序时，整个应用程序会被重新下载(其他移​​动平台也可能以这种方式工作，但我只接触过这些平台)。

为什么需要重新下载整个应用程序进行更新而不是增量更新？

这似乎非常低效，尤其是当您处理大型应用程序时。

Answer 1

您的基本问题不适用于 iOS，as of 6.0 :

Starting with iOS 6, the app store will automatically produce an update package for all new versions of apps submitted to the store. This package is optimized for updating an app from one version to another, and contains files that have changed between the prior version of an app and the new version of the app, excluding files that have not changed.

When used optimally, an update package is significantly smaller to download than the full package of the app and the update will install more quickly. Also, in many cases, this mechanism allows updates to large apps to be downloadable over cellular networks where app downloads are subject to a size limit.

In addition to new content, the update package contains instructions on how to transform the prior version of the app into the new version of the app. New files will be added, modified files will be replaced with their updated counterpart, and deleted files will be removed as part of this transformation. As far as the developer and user are concerned, this process is entirely transparent and the resulting updated app will be indistinguishable from a full download of the corresponding updated version of their app.

所以，是的，可以在移动平台上进行增量应用程序更新以及增量操作系统更新。此功能只需由操作系统供应商添加即可。