Android - How to fully load an activity in the background

Question

The goal is to run and load a second activity in the background when the user is still in the first activity. The second activity is pretty heavy and it takes time to load; so I need to show the second activity after it's loaded and ready.

public void onButtonClick(View view){
    Intent intent = new Intent(this, MainActivity.class);
    intent.putExtra("user_input", userInput.getText().toString());

    startActivity(intent);
}

Can I modify the above code in order to load the second activity in the background?

If you're doing some heavy task move them into the background service or thread. — VinayagaSundar, Sep 01 '17 at 05:47
Use Progress loader to tell your about loading the data in background.. — VinayagaSundar, Sep 01 '17 at 05:55
Please don't do any heavy task in activity. If need to load some heavy data then process it in background using Service, in this time engage user in other task. If activity takes more then 3 seconds it gives very very bad impact on user. You can also load activity and start a thread or asynktask to load any heavy data. — ParikshitSinghTomar, Sep 01 '17 at 06:00

score 2 · Accepted Answer · edited Jun 20 '20 at 09:12

if you have heavy task in you second activity than move your heavy task into the background service or thread.

you can use AsyncTask for background work

AsyncTask enables proper and easy use of the UI thread. This class allows you to perform background operations and publish results on the UI thread without having to manipulate threads and/or handlers.

Android AsyncTask is an abstract class provided by Android which gives us the liberty to perform heavy tasks in the background and keep the UI thread light thus making the application more responsive.

example of AsyncTask

link 1

link 2

link 3

you can display data in second activity while using AsyncTask — AskNilesh, Sep 01 '17 at 05:56

score 1 · Answer 2 · answered Sep 01 '17 at 05:55

For that you want to use Services

Step-1 Create class file which extend Service like below

public class TestService extends Service {
@Override
    public void onCreate() {
        // cancel if already existed  
    }
}

Step-2 Place your service class inside AndroidManifest.xml

<service android:name=".TestService" />

Step-3 Use Intent for call service like this

Intent intent = new Intent(this,TestService.class);
startActivity(intent);

score 1 · Answer 3 · answered Sep 01 '17 at 06:38

You can't start activity from background because it is intended to run from Android Main thread.Instead of loading activity from background you can do your heavy work those are not related to UI in background thread you can use AsyncTask, Handler or even IntentService for the same and then get result on Main thread and update your UI. Try to avoid nested layout as much as possible and do not process any heavy task in main thread.

score 0 · Answer 4 · answered Apr 13 '23 at 16:26

Alternative option: Show a loading screen when user clicks button. This will give the user visual feedback while your second activity is being created...so your app doesn't seem like it's lagging.

public void onButtonClick(View view){
    setContentView(R.layout.loading_screen);
    Intent intent = new Intent(this, MainActivity.class);
    intent.putExtra("user_input", userInput.getText().toString());

    startActivity(intent);
}

Android - How to fully load an activity in the background

4 Answers4