android fragment addToBackStack(null) :how to add the same fragment to stack just one time?
android, fragment
Solution
When adding your `Fragment` to the backstack you should also pass a `TAG` to be able to identify that `Fragment`:
.addToBackStack(SettingsFragment.TAG);
Prior to adding the `Fragment` you will be able to check if this `Fragment` is allready in the backstack using :
getFragmentMangager().findFragmentByTag(SettingsFragment.TAG);
This will return `null` if the `Fragment` is not allready added.
Problem
when fragment use addToBackStack(null) method and click a method many times in an activity, the fragment page will save to back stack everytime, when I press back key, it will restore the same page, how to add the same fragment to stack just one time? ``` mSettingBtn.setOnClickListener(new OnClickListener() { @Override public void onClick(View v) { SettingFragment settingFragment = new SettingFragment(); FragmentTransaction transaction = getFragmentManager().beginTransaction(); transaction.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_FADE); transaction.replace(R.id.left_framelayout, settingFragment); transaction.addToBackStack(null); transaction.commit(); } }); ```