android studio tutorial save information in states

The saved data that the system uses to restore the previous state is called the instance state and is a collection of key-value pairs stored in a Bundle object.īy default, the system uses the Bundle instance state to save information about each View object in your activity layout (such as the text value entered into an EditText widget). However, if the system destroys the activity due to system constraints (rather than normal app behavior), then although the actual Activity instance is gone, the system remembers that it existed such that if the user navigates back to it, the system creates a new instance of the activity using a set of saved data that describes the state of the activity when it was destroyed.

When your activity is destroyed because the user presses 'Back' or the activity finishes itself, the system's concept of that Activity instance is gone forever because the behavior indicates the activity is no longer needed.

The system may also destroy the process containing your activity to recover memory if the activity is in the Stopped state and hasn't been used in a long time, or if the foreground activity requires more resources. Saving and restoring activity state There are a few scenarios in which your activity is destroyed due to normal app behavior, such as when the user presses the Back button or your activity signals its own destruction by calling the finish() method. Import Documentation that explains about saving states and a very good article on saving states in activity and fragment.

I have an application with checkboxes, How can i save them?Īnd my main.class is: package com.boodschappen

Android studio tutorial save information in states