The activity life cycle refers to the six stages an Android activity goes through in its lifetime. These are: onCreate (), onStart (), onResume (), onPause (), onStop (), and onDestroy ().
When an Android system starts an activity, it calls onCreate (). This is where the activity’s main () ethod is executed. After onCreate () s complete, the system calls onResume (). This is where the activity is resumed from the background.
In between onResume () nd onPause (), the system calls onStart (). onStart () nitializes the activity’s resources and sets it into the running state. After onStart () s complete, the system calls onResume () gain.
In between onResume () nd onStop (), the system calls onPause (). onPause () uspends the activity until the user presses the back button or performs some other action that causes it to resume.
When the activity is paused, the system calls onStop (). onStop () tops the activity and removes it from the running state.
Finally, when the activity is stopped, the system calls onDestroy (). onDestroy () estroys the activity and releases any resources it allocated.
This is important
Activity life cycle is a model that describes the different stages that an activity goes through in an Android device. The activity life cycle starts with the activity creation, and ends with the activity destruction. The activity creation process is followed by the activity start phase, in which the activity is given an initial start time. The activity then enters the activity run phase, during which the activity is executing its code. The activity enters the activity paused state if it is not currently being executed. The activity exits the activity run phase and enters the activity paused state if the user presses the back button. The activity is then destroyed if the user presses the back button again or if the device is turned off.
What Does Activity Lifecycle Mean
Activity is one of the building blocks of Android OS. In simple words Activity is a screen that user interact with. Every Activity in android has lifecycle like created, started, resumed, paused, stopped or destroyed. These different states are known as Activity Lifecycle.
Activity Lifecycle is a way to manage the different states of an Activity. Activity can be in one of the following states:
-Created: When an Activity is first created, it is in the created state.
-Started: When an Activity is first started, it is in the started state.
-Resumed: When an Activity is resumed, it is in the resumed state.
-Paused: When an Activity is paused, it is in the paused state.
-Stopped: When an Activity is stopped, it is in the stopped state.
-Destroyed: When an Activity is destroyed, it is in the destroyed state.
What Are Callback Methods in Android
Callback methods are a feature of Android that allow applications to request information from underlying security services. When an application calls a security service using a callback, the service is given the opportunity to return any information that the application might need in order to complete its task. This allows applications to interact with the security services in a way that is transparent to the user, and it can also allow the security services to interact with the application in a way that is more efficient. callback methods are a commonly used feature of Android, and they are often used to provide the means for applications to interact with the security services.
What Is the Difference Between Activity and Services in Android
Android provides an application with the ability to run long-running operations in the background. This is done by providing the application with the service feature. Activities represent a single screen with a user interface.
What Are Launch Modes in Android
Android has 4 launch modes: Standard, Single Task, Single Top, and Single Instance.
In Standard mode, an activity is started by the system and all new actions are linked to the existing task. This is the default mode for activities.
In Single Task mode, an activity is started by the system and only the current task is executed. This is useful for applications that need to run in a single process.
In Single Top mode, an activity is started by the system and the task is placed at the top of the screen. This is useful for applications that need to be accessible from multiple locations.
In Single Instance mode, an activity is started by the system and the task is executed as a new instance. This is useful for applications that need to run in a separate process.
What Is the Fragment Lifecycle in Android
When the app starts up, all the fragments are in the LoaderState. This state is the first stage of the fragment lifecycle and it lasts until the user navigates away from the fragment or the app is force closed. Once the user navigates away from the fragment, the fragment transitions to the ScreenState. The ScreenState is the second stage of the fragment lifecycle and it lasts until the fragment is removed from the screen or the app is force closed. When the fragment is removed from the screen, the fragment transitions to the FragmentState. The FragmentState is the final stage of the fragment lifecycle and it lasts until the fragment is destroyed.
What Is a Service in Android
Services are applications components that can run in the background and don’t provide a user interface. Once started, a service might continue running for some time, even after the user switches to another application. Services are useful for performing long-running operations, like listening for network connections or managing files.
What Is Visible Activity in Android
When an Activity is in the foreground, the user can see it on-screen. However, if the Activity is in the background, the user cannot see it. When an Activity is in the background, the operating system can still use the Activity to do things like keep track of the battery level or send notifications.
What Is Intent in Android Studio
Intent is defined as an intention or purpose. Intent can be used with the startActivity () ethod to invoke an activity, broadcast receivers etc. Intent can also be used with the putExtra () ethod to pass additional data to an activity. Intent can also be used with the IntentFilter class to restrict the activity that is invoked. Intent is an important part of Android programming and is used to pass information between components.
In a nutshell
So the activity life cycle is when the Android system starts, resumes, pauses, and stops the activity.
