Try this,

public class MainActivity extends AppCompatActivity { private static final String TAG = "MainActivity"; Button click; @Override protected void onCreate(Bundle savedInstanceState) { Log.i(TAG, "onCreate()"); super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); click = findViewById(R.id.button1); click.setOnClickListener(v -> { Handler handler = new Handler(); handler.postDelayed(() -> { // This will be executed after 10 seconds getLifecycle().addObserver(new MyObserver()); }, 10000); }); } private class MyObserver implements LifecycleObserver { @OnLifecycleEvent(Lifecycle.Event.ON_RESUME) public void onResume() { // This will be called when the activity is in the resumed state DialogController.ShowErrorDialog(MainActivity.this, R.string.string_error_dialog); } } } 

Try this,

public class MainActivity extends Activity { private static final String TAG = "MainActivity"; Button click; @Override protected void onCreate(Bundle savedInstanceState) { Log.i(TAG, "onCreate()"); super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); click = findViewById(R.id.button1); click.setOnClickListener(v -> { Handler handler = new Handler(); handler.postDelayed(() -> { // This will be executed after 10 seconds getLifecycle().addObserver(new MyObserver()); }, 10000); }); } private class MyObserver implements LifecycleObserver { @OnLifecycleEvent(Lifecycle.Event.ON_RESUME) public void onResume() { // This will be called when the activity is in the resumed state DialogController.ShowErrorDialog(MainActivity.this, R.string.string_error_dialog); } } }