Android开发的一些知识

一些Android开发的知识。

  1. At a high level, what does the Android architecture look like?

    https://aprildown.xyz/2019/02/03/android-requirements-architecture/

  2. At a high level, what happens when you hit the build button on Andorid Studio?

    https://aprildown.xyz/2019/02/03/android-requirements-start-button/

  3. What happens when you install an application on the device?

    https://stackoverflow.com/questions/7773360/what-exactly-happens-when-i-install-an-android-application

  4. How Dalvik and ART VMs work?

    https://aprildown.xyz/2019/02/15/android-requirements-dalvik-art/

  5. How does Inter-Process-Communication work on Android?

    来自Linux的跨进程通信,Android有自己的实现。用于不同Android Components之间如何通信。有多种机制:Intents、Bundles、Binders、Service、BroadcastReceivers。这些实现为通信提高了安全性。

    一些情况可以需要ALDL来实现跨进程通信:https://developer.android.com/guide/components/aidl

  6. How are apps sandboxed and why does it matter?

    https://source.android.com/security/app-sandbox

    借用了Linux的用户权限系统来给每个应用提供各自的权限,达到了应用分离、沙箱的效果。默认情况下,普通应用没有跟其他应用和系统应用互动的权限。

  7. Processes and application lifecycle

    https://developer.android.com/guide/components/activities/process-lifecycle

    应用在需要运行时,创建进程。再不再运行且系统需要内存时回收。系统根据一个应用正在运行中的组件来给应用分等级,并在需要内存时,从低等级开始回收。

    BroadcastReceiver在返回之后,系统就会认为它没用了。需要回收时就会清理掉它和它产生的线程。