Question

I’m having trouble putting this problem into searchable terms. I’m working on an Android application, and specifically the splash screen for my app. The app needs to fetch data from an external web service (a blocking function call), while it does this the user gets a nice title, image and progress bar. When the data arrives the user is redirected to the main menu. Its a simple screen, everything being defined in the xml layout file, my problem is that I just get a black screen for a few seconds and then the main menu. If I press back I get the splash screen with the progress bar spinning away happily.

Here is what I have so far:

public class SplashActivity extends Activity{
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.splash);
    }

    @Override
    public void onStart(){
        super.onStart();
        DatabaseManager db = new DatabaseManager(this.getBaseContext());
        db.fetchExternCatalog(); //doesnt return until data arrives
        Intent intent = new Intent().setClass(this, MainMenuActivity.class);
        startActivity(intent);
    }
}

It seems the screen isnt actually drawn until the activity is running (after onCreate(), onStart(), etc). I thought onStart() would be the perfect place to put this, but apparently not.

So how do I draw everything on the screen and make my blocking function call after so the user actually sees the splash screen while the data is downloaded?

Answer 1

You’re going to be locking up the UI thread which is why i believe you are seeing a black screen. Use an AsyncTask or create your own thread pool for DB operations.

As far as hitting the back button and seeing your old activity, You need to tell android not to store the activity in it’s stack. This should help:

http://developer.android.com/guide/topics/fundamentals/tasks-and-back-stack.html