[android] How to finish current activity in Android

You need to call finish() from the UI thread, not a background thread. The way to do this is to declare a Handler and ask the Handler to run a Runnable on the UI thread. For example:

public class LoadingScreen extends Activity{
    private LoadingScreen loadingScreen;
    Intent i = new Intent(this, HomeScreen.class);
    Handler handler;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        handler = new Handler();
        setContentView(R.layout.loading);

        CountDownTimer timer = new CountDownTimer(10000, 1000) //10seceonds Timer
        {
             @Override
             public void onTick(long l) 
             {

             }

             @Override
             public void onFinish() 
             {
                 handler.post(new Runnable() {
                     public void run() {
                         loadingScreen.finishActivity(0);
                         startActivity(i);
                     }
                 });
             };
        }.start();
    }
}