Develop Reference

Fragments overlapping while using replace() [duplicate]

I have a fragment inside a group activity and I want to replace it with another fragment:
FragmentTransaction ft = getActivity().getFragmentManager().beginTransaction();
SectionDescriptionFragment bdf = new SectionDescriptionFragment();
ft.replace(R.id.book_description_fragment, bdf);
ft.setTransition(FragmentTransaction.TRANSIT_FRAGMENT_OPEN);
ft.addToBackStack(null);
ft.commit();
It works fine when it is done as a seperate project without using activity group, every thing works fine in log cat as control goes inside getview(), but no view is visible, not even any exception arises, I want the book detail fragment to be replaced by section detail fragment.
Xml of book detail fragment has id book_description_fragment and xml for section description fragment has id section_description_fragment.
The above code is in onClick method of an item, I want that when user taps on an item in horizontal scroll view, then the fragment changes.

Fragments that are hard coded in XML, cannot be replaced. If you need to replace a fragment with another, you should have added them dynamically, first of all.
Note: R.id.fragment_container is a layout or container of your choice in the activity you are bringing the fragment to.
// Create new fragment and transaction
Fragment newFragment = new ExampleFragment();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack if needed
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();

Please see this Question
You can only replace a "dynamically added fragment".
So, if you want to add a dynamic fragment, see this example.

I've made a gist with THE perfect method to manage fragment replacement and lifecycle.
It only replace the current fragment by a new one, if it's not the same and if it's not in backstack (in this case it will pop it).
It contain several option as if you want the fragment to be saved in backstack.
=> See Gist here
Using this and a single Activity, you may want to add this to your activity:
#Override
public void onBackPressed() {
int fragments = getSupportFragmentManager().getBackStackEntryCount();
if (fragments == 1) {
finish();
return;
}
super.onBackPressed();
}

Use the below code in android.support.v4
FragmentTransaction ft1 = getFragmentManager().beginTransaction();
WebViewFragment w1 = new WebViewFragment();
w1.init(linkData.getLink());
ft1.addToBackStack(linkData.getName());
ft1.replace(R.id.listFragment, w1);
ft1.commit();

Use ViewPager. It's work for me.
final ViewPager viewPager = (ViewPager) getActivity().findViewById(R.id.vp_pager);
button = (Button)result.findViewById(R.id.button);
button.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
viewPager.setCurrentItem(1);
}
});

hope you are doing well.when I started work with Android Fragments then I was also having the same problem then I read about
1- How to switch fragment with other.
2- How to add fragment if Fragment container does not have any fragment.
then after some R&D, I created a function which helps me in many Projects till now and I am still using this simple function.
public void switchFragment(BaseFragment baseFragment) {
try {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.setCustomAnimations(android.R.anim.slide_in_left, android.R.anim.slide_out_right);
if (getSupportFragmentManager().findFragmentById(R.id.home_frame) == null) {
ft.add(R.id.home_frame, baseFragment);
} else {
ft.replace(R.id.home_frame, baseFragment);
}
ft.addToBackStack(null);
ft.commit();
} catch (Exception e) {
e.printStackTrace();
}
}
enjoy your code time :)

you can use simple code its work for transaction
Fragment newFragment = new MainCategoryFragment();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.content_frame_NavButtom, newFragment);
ft.commit();

You Can Use This code
((AppCompatActivity) getActivity()).getSupportFragmentManager().beginTransaction().replace(R.id.YourFrameLayout, new YourFragment()).commit();
or You Can This Use Code
YourFragment fragments=(YourFragment) getSupportFragmentManager().findFragmentById(R.id.FrameLayout);
if (fragments==null) {
getSupportFragmentManager().beginTransaction().replace(R.id.FrameLayout, new Fragment_News()).commit();
}

I change fragment dynamically in single line code
It is work in any SDK version and androidx
I use navigation as BottomNavigationView
BottomNavigationView btn_nav;
FragmentFirst fragmentFirst;
FragmentSecond fragmentSecond;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_search);
fragmentFirst = new FragmentFirst();
fragmentSecond = new FragmentSecond ();
changeFragment(fragmentFirst); // at first time load the fragmentFirst
btn_nav = findViewById(R.id.bottomNav);
btn_nav.setOnNavigationItemSelectedListener(new BottomNavigationView.OnNavigationItemSelectedListener() {
#Override
public boolean onNavigationItemSelected(#NonNull MenuItem menuItem) {
switch(menuItem.getItemId()){
case R.id.menu_first_frag:
changeFragment(fragmentFirst); // change fragmentFirst
break;
case R.id.menu_second_frag:
changeFragment(fragmentSecond); // change fragmentSecond
break;
default:
Toast.makeText(SearchActivity.this, "Click on wrong bottom SORRY!", Toast.LENGTH_SHORT).show();
}
return true;
}
});
}
public void changeFragment(Fragment fragment) {
getSupportFragmentManager().beginTransaction().replace(R.id.fragment_layout_changer, fragment).commit();
}

In kotlin you can do:
// instantiate the new fragment
val fragment: Fragment = ExampleFragment()
val transaction = supportFragmentManager.beginTransaction()
transaction.replace(R.id.book_description_fragment, fragment)
transaction.addToBackStack("transaction_name")
// Commit the transaction
transaction.commit()

This will work if you're trying to change the fragment from another fragment.
Objects.requireNonNull(getActivity()).getSupportFragmentManager()
.beginTransaction()
.replace(R.id.home_fragment_container,new NewFragment())
NOTE As stated in the above answers, You need to have dynamic fragments.

You can use fragment-ktx
// If you are in fragmet
childFragmentManager.beginTransaction()
// or if you are in activiry
supportFragmentManager.beginTransaction()
// Create and commit a new transaction
supportFragmentManager.commit {
setReorderingAllowed(true)
// Replace whatever is in the fragment_container view with this fragment
replace<ExampleFragment>(R.id.fragment_container)
}

To replace a fragment with another one do this, Note that R.id.fragment comes from the id that you give to the first tag of the fragment in the XML.
barAudioPlaying.setOnClickListener(view -> {
getActivity().getSupportFragmentManager()
.beginTransaction()
.replace(R.id.fragment,new HomeFragment())
.commit();

how to remove fragment over an activity layout

I am really new to android development. I have created a simple main activity and add an icon on top left. Clicking it I can show a blank fragment.on my screen replacing a layout which is loaded in onCreate method. Now clicking another icon I want to hide that fragment and load that layout again. How to do that?? any helps??
Below is my code
//part of oncreate where my layout is loaded
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
}
// part of code when icon clicked and fragment is loaded
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
BlankFragment frag = new BlankFragment();
fragmentTransaction.replace(R.id.content_main, frag);
fragmentTransaction.commit();
//another nearby icon clicked
//now i want to replace this fragment from content_main layout
//what code to add??

If I got your question right, then this is the right answer I guess.
//keep track of all fragments you add by tagging
fragmentTransacaction.add(R.id.content, new FragA(), "first");
//and when removeing
Fragment f = getFragmentManager().findFragmentByTag("first");
if(f!=null) fragmentTransac.remove(f);
fragmentTransac.commit();
I got this from here

You can toggle visibilty by below code.
public void toggleVisibility(Fragment fragment){
FragmentTransaction transaction = getFragmentManager().beginTransaction();
if (fragment.isHidden()) {
transaction.show(fragment);
} else {
transaction.hide(fragment);
}
transaction.commit();
}

Fragment show/hide is not working at all

I have been trying to build an android app for the purpose of understanding basic concepts behind fragments. But I am completely unable to show and hide fragment. Here is my code for onClickListner
final FragmentManager fragmentManager = getFragmentManager();
b.setOnClickListener(new View.OnClickListener() {
#TargetApi(Build.VERSION_CODES.HONEYCOMB)
public void onClick(View v) {
FragmentTransaction ft = fragmentManager.beginTransaction();
PM_Fragment pm_fragment = new PM_Fragment();
ft.replace(android.R.id.content, pm_fragment);
if (pm_fragment.isHidden()) {
fragmentManager.beginTransaction()
.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
.show(pm_fragment)
.commit();
b.setText("Hide");
} else {
fragmentManager.beginTransaction()
.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out)
.hide(pm_fragment)
.commit();
b.setText("Show");
}
}
});
Fragment is simply a text line in my case. And what the button is supposed to do is toggle the visibility of the fragment.
Can anybody tell me what is wrong with this code?
And by not working, I mean that button does nothing when tapped, except for changing its text from "hide" to "show" and after that it keeps "show", no matter how many times you tap it. And this process has no effect on the behaviour of fragment at all.

I really don't understand what you are trying to do here, but you never commit ft so your Fragment is never added to the Activity. I also don't understand the purpose of the two inner FragmentTransaction, but it is save to say that you DO NOT need them at all...
Define this globally:
private PM_Fragment pmFragment = new PM_Fragment();
And your OnClickListener should look like this:
b.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction ft = fragmentManager.beginTransaction();
ft.setCustomAnimations(android.R.animator.fade_in, android.R.animator.fade_out);
if(pmFragment.isAdded()) {
ft.remove(pmFragment);
} else {
ft.replace(android.R.id.content, pmFragment);
}
ft.commit();
}
});
IMPORTANT: For FragmentTransactions to work, the Fragment has to have been added in code! If you add them in XML then they cannot be affected by FragmentTransactions! So if added your Fragment like this:
<fragment
android:layout_width="match_parent"
android:layout_height="match_parent"
android:name="at.example.fragments.SomeFragment" />
Or with some other similar method than I am sure that this is at least part of the problem. You need to add your Fragment solely in code like this:
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
if (savedInstanceState == null) {
SomeFragment fragment = SomeFragment.newInstance();
FragmentManager manager = getSupportFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.flFragmentContainer, fragment);
transaction.commit();
}
}
Just replace the <fragment /> tag with something like this in the layout:
<FrameLayout
android:id="#+id/flFragmentContainer"
android:layout_width="match_parent"
android:layout_height="match_parent" />
It will serve as a container for the Fragment you want to add. You can use the FragmentTransaction above to add the Fragment to this FrameLayout.

Layout duplicating itself on screen rotation

I have a layout that has an EditText and a Button. I <include> it in my main layout.
I'm having a weird issue with the layout and rotation. It seems to duplicate itself when the device (physical) is rotated, messing up the text and layout.
Here it is on first open, after I add some extra garble:
DSC_0013 is in the EditText on launch of the fragment.
Then, I rotate the phone and add some different garble:
And you can see the issue pretty clearly. At first, I thought it was just the EditText messing up. But if I add enough text to make a new line:
I can see that the button gets messed up too.
I do override onSaveInstanceState, but in it I don't touch the EditText or its value, it's strictly used for something else.
What's happening and how do I fix it?

Fixed it!
Turns out it wasn't the view duplicating itself, or the EditText, or the Button. It was the entire fragment.
In my Activity's onCreate, I add the fragment to an xml layout:
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
And onCreate was being called every time I rotated the phone (as it's meant to). So I put in a check to see if the activity is being run for the first time, and it works great.
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
if (savedInstanceState == null) {
FragmentManager fragmentManager = getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
} else {
fileDetailsFragment = (FileDetails) getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
}

You can also setRetainedInstance(true) on your fragment, then try to get the Fragment form de FragmentManager.findFragmentById(int) or FragmentManager.findFragmentByTag(String), and if it returns null it meant you had to create a new instance of your Fragment.
private FileDetails fileDetailsFragment;
public void onCreate(Bundle savedInstanceState) {
...
FragmentManager fragmentManager = getSupportFragmentManager();
fileDetailsFragment = (FileDetails) getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
if (fileDetailsFragment == null) {
fileDetailsFragment = new FileDetails(FileData);
}
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
}

In some cases, the value of savedInstanceState may be null after rotation, so it is better to add another condition:
FragmentManager fragmentManager = getSupportFragmentManager();
if (savedInstanceState == null &&
fragmentManager.getFragments().size() == 0) {
FragmentTransaction fragmentTransaction = fragmentManager
.beginTransaction();
fileDetailsFragment = new FileDetails(fileData);
fragmentTransaction.add(R.id.DetailsHolder, fileDetailsFragment);
fragmentTransaction.commit();
} else {
fileDetailsFragment = (FileDetails)
getSupportFragmentManager().findFragmentById(R.id.DetailsHolder);
}

Memory issues - fragments

I recently refactored a application and replaced a ViewFlipper for a FrameLayout on which I swap between Fragments.
Each time user request one of the views:
public void showLibraryOf(long publisherId) {
library = new DownloadLibraryFragment(id, viewFactory());
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.container, library);
ft.commit();
library.setAdapterObserver(this);
}
public void showMyLibraryOf(long publisherId) {
myLibrary = new MyLibraryFragment(id, viewFactory());
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.container, myLibrary);
ft.commit();
}
public void showHelp() {
FragmentTransaction ft = getFragmentManager().beginTransaction();
ft.replace(R.id.container, new HelpFragment());
ft.commit();
}
I create a new Fragment and replace the old one. Those being removed from screen get onDestroy called, but the memory consumed by the bitmaps I load on the screen does not get removed, so the application crashes after some swap between the fragments.
I also tried to remove references at onDestroy
#Override
public void onDestroyView() {
destroy();
super.onDestroyView();
adapter.clear();
adapter.clearObservers();
adapter.notifyDataSetChanged();
view.setAdapter(new ArrayAdapter<Journal>(getActivity(), 0));
adapter = null;
view = null;
}
But the memory keeps growing.
Anyone knows any solution? maybe reuse fragments? effectively destroy it? I'm listening.

I forget which stackoverflow question I originally pulled this code from, but one method that seems to work well is to override onAttachFragment of the FragmentActivity, and then store a WeakReference to each fragment passed in. Then, instead of using the replace method of a FragmentTransaction, you recycle all the fragments (as relevant for the case).
Here's an example of additional members and methods on a FragmentActivity that creates a default fragment in onCreate and responds to changes via onNewIntent:
private List<WeakReference<Fragment>> mFragments =
new ArrayList<WeakReference<Fragment>>();
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.main);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.fragment_container, MyFragment.newInstance("default"));
ft.commit();
}
#Override
protected void onNewIntent(Intent intent) {
setIntent(intent);
String section = intent.getStringExtra("section");
recycleFragments();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.add(R.id.fragment_container, MyFragment.newInstance(section));
ft.commit();
}
#Override
public void onAttachFragment(Fragment fragment) {
mFragments.add(new WeakReference<Fragment>(fragment));
}
private void recycleFragments() {
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
for (WeakReference<Fragment> ref : mFragments) {
Fragment fragment = ref.get();
if (fragment != null) {
ft.remove(fragment);
}
}
ft.commit();
}
Now if you monitor the heap, you should notice it's not blowing up in size. This solution mostly comes into play when you have nested fragments containing bitmaps which for some reason don't seem to get recycled properly. I'd love a more elegant solution but this one works.