25.1 Introducing Apply Changes

In early versions of Android Studio, each time a change to a project needed to be tested Android Studio would recompile the code, convert it to Dex format, generate the APK package file and install it on the device or emulator. Having performed these steps the app would finally be launched ready for testing. Even on a fast development system this is a process that takes a considerable amount of time to complete. It is not uncommon for it to take a minute or more for this process to complete for a large application.

Apply Changes, in contrast, allows many code and resource changes within a project to be reflected nearly instantaneously within the app while it is already running on a device or emulator session.

Consider, for the purposes of an example, an app being developed in Android Studio which has already been launched on a device or emulator. If changes are made to resource settings or the code within a method, Apply Changes will push the updated...