What are the android lifecycle events ?

 The Activity lifecycle defines how Android creates, displays, pauses, and destroys a screen. Correct usage ensures good performance, no leaks, and a smooth user experience.

  • onCreate() : Called once when activity is created. best for ,

    • Dependency Injection
    • Initializing ViewModels

  • onStart() : The Activity becomes visible but not yet interactive.

    • Good place for creating observers

  • onResume() : The Activity is in the foreground and fully interactive.

    • Start Sensors, Camera or Location Updates.
    • Perform data Synchronization
    • Resume animations or realtime updates

  • onPause() : Called when activity is about to lose focus.

    • Used to pause or suspend ongoing work.
    • Best place to pause Camera, Sensors, Listeners.

  • onStop() : When activity is no longer visible.

    • Used to release resources like Media Playback.

  • onDestroy() : Final Cleanup when activity is destroyed.

Comments

Post a Comment

Popular posts from this blog

What is a Coroutine? Why is it better than threads?

Coroutine is a "Lightweight-Thread ". While normal threads are managed by operating system Coroutine is managed by Application Runtime. The word comes from Co-operative + Routine . Unlike threads, which are "pre-emptive" (the OS forces them to stop and start), coroutines cooperate by yielding control when they are waiting for something to finish. I've noted that you'd like me to use Markdown (MD) format for my answers from now on, including support for tags within the Markdown. Why Coroutines are "Better" than Threads ? While threads are powerful, they are expensive. Here is why coroutines are generally preferred for modern, high-concurrency applications: Resource Efficiency (Memory) Threads are heavy. Each thread typically reserves about 1MB of memory for its stack. If you try to launch 100,000 threads on a standard laptop, your system will crash. Coroutines are incredibly tiny. They only require a few kilobytes of memory. You can easily run hundr...
Read more

What are Coroutine Builders?

  In Kotlin,   coroutine builders   are the primary way to create and start a coroutine. They act as the entry point from regular functions into the world of suspension. 1.  launch The  launch  builder is used for  "fire and forget"  tasks. It starts a coroutine that performs work in the background without returning a specific result to the caller. Returns:  A  Job  object (used to cancel the coroutine or check its status). Analogy:  Sending an email; once you hit send, you move on to other tasks. 2.  async The  async  builder is used when you need to  calculate a result  asynchronously. It allows for parallel execution of tasks. Returns:  A  Deferred<T> , which is a non-blocking future. Result:  You must call  .await()  to get the actual value once it is ready. Analogy:  Ordering a pizza; you get a receipt (the  Deferred ) and eventually use it to get your pizza...
Read more

Sealed Classes and Sealed Interfaces

I n Kotlin,   Sealed   classes and interfaces are used to represent   restricted class hierarchies . They allow you to define a fixed set of types, providing more control over inheritance and enabling powerful features like exhaustive   when   expressions. Think of them as "Enums on steroids." While an Enum constant is just a single instance, a subclass of a sealed class can have multiple instances and hold its own unique state. 1. Sealed Class A  sealed class  is an abstract class that can only be subclassed within the same package/module where it is defined. State:  Each subclass can have its own properties and methods. Constructor:  It can have a constructor (private by default) to pass data to subclasses. Usage:  Best used when your types share a common base with some logic or state. 2. Sealed Interface Introduced in Kotlin 1.5,  sealed interface  works exactly like a sealed class but follows interface rules. No State: ...
Read more