Understanding Android Activity Lifecycle


Activity is the first building block of an Android App. If you are writing an app which will interact with user in some way then you will need an activity. Activity handles the UI of an Android App. In our blog today we will go through some of the theoretical concepts behind the activities

An activity has different stages in its lifecycle. The following is the list of the stages

    Created – The activity has been created but is not visible
    Started – The activity is in the process of being displayed and is only partially visible
    Resumed – The activity is fully visible and can be interacted with
    Paused – The activity is only partially visible
    Stopped – The activity is not visible and may be either restarted or destroyed
    Destroyed – The activity is no longer in memory

Each of these states are reached via method calls and we summarize them as follows

onCreate ()– It takes the activity to created state. It is the first method to be called
onStart() – It is called to get to the started state. It follows onCreate.
onResume() – This calls the Resume state which is the most important of the states. It is called after onStart(). The activity stays in this state the longest.
onPause() – It gets activity to the Paused state. It gets called on the Resumed state.
onStop() – It takes the activity to Stop state
onRestart() – It takes the activity from stop state to starting state.
onDestroy() – It takes the activity to destroyed state

Attributes – The above methods have the following attributes

    They are called before the state is entered
    Can be overridden
    Must call through Super

To get a detail description check out our video here

Hope you have enjoyed our blog today.