Handler probably delivers a Runnable to an Activity that was recycled. Proper use of Handler
is like
private Handler mHandler;
private TextView mTextView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
mHandler = new Handler();
setContentView(R.layout.yourView);
mTextView = findViewById(R.id.text);
}
@Override
protected void onStart() {
super.onStart();
//start updating every time Activity is started
handler.postDelayed(mTimer, oneMinuteDelay);
}
@Override
protected void onStop() {
super.onStop();
//make sure to remove all messages
handler.removeCallbacksAndMessages(null);
}