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How to add an Item Click Listener in `RecyclerView.Adapter' using CardView Item

How can I add an Item Click Listener for my `RecyclerView.Adapter'
when the user clicks on the Card View item, Data sent to the PostContent Fragment?
Also, is it possible to send the data from this adapter to the new fragment using intent?
Please note my code:
public class PostDataAdapter extends RecyclerView.Adapter<PostDataAdapter.MyViewHolder> {
private List<PostData> PostDataList ;
public static class MyViewHolder extends RecyclerView.ViewHolder {
public TextView vPostContent, vPostDate, vPostAuthor, vPostTitr,VPostLikes,VPostViews;
public ImageView vPostPhoto;
public MyViewHolder(View v) {
super(v);
vPostContent = v.findViewById(R.id.PostContentTv);
vPostDate = v.findViewById(R.id.PostDateTv);
vPostAuthor = v.findViewById(R.id.PostAuthorTv);
vPostTitr = v.findViewById(R.id.PostTitrTv);
vPostPhoto = v.findViewById(R.id.PostPhoto);
VPostLikes=v.findViewById(R.id.PostLikeTv);
VPostViews=v.findViewById(R.id.PostViewTv);
}
}
public PostDataAdapter(List<PostData> postDataList) {
PostDataList = postDataList;
}
#Override
public PostDataAdapter.MyViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.row_posts, parent, false);
MyViewHolder vh = new MyViewHolder(v);
return vh;
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.vPostDate.setText(PostDataList.get(position).getPostDate());
holder.vPostTitr.setText(PostDataList.get(position).getPostTitr());
holder.vPostContent.setText(PostDataList.get(position).getPostContent());
holder.vPostAuthor.setText(PostDataList.get(position).getPostAuthor());
holder.VPostViews.setText(PostDataList.get(position).getPostViews());
holder.VPostLikes.setText(PostDataList.get(position).getPostLikes());
new DownloadImageTask(holder.vPostPhoto).execute(PostDataList.get(position).getImgpost());
}
#Override
public int getItemCount() {
return PostDataList.size();
}
}

To add a ItemCLickListener for RecyclerView, you need to implement a custom Interface which the Fragment will implement. When the list item is clicked, then the callback function of the interface is called.
CustomItemClickListener.java:
public CustomItemClickListener {
void onItemClick(Object data);
}
Just add these to the PostDataAdapter:
PostDataAdapter.java:
private CustomItemClickListner clickListener;
public PostDataAdapter(CustomItemClickListner listener, List<PostData> postDataList) {
PostDataList = postDataList;
clickListener = listener
}
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.vPostCardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
// Modify the parameters of the function according to what you want to send to the fragment
// As soon as this is called, the `onItemClick` function implemented in the Fragment gets called.
clickListener.onItemClick(Object data);
}
});
}
Fragment.java:
CustomFragment extends Fragment implements CustomItemClickListener {
public CustomFragment() {
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view;
PostDataAdapter adapter = new PostDataAdapter(this, new ArrayList<PostData>)
return view;
}
#Override
public void onItemClick(Object data) {
// Handle the data sent by the adapter on item click
}
}

Yu cand send data from Adapter to a Fragment with Intent:
Fragment fragment = new tasks();
FragmentManager fragmentManager = context.getSupportFragmentManager(); // this is the context of the Activity
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
Bundle bundle=new Bundle();
bundle.putString("name", "Osmar Cancino"); //key and value
//set Fragmentclass Arguments
fragment.setArguments(bundle);
fragmentTransaction.replace(R.id.content_frame, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
Although my suggestion is to manage the flow of screens from the parent activity, and manage the data through a Callback, even with a custom Interface

There are two ways you can do this.
Write recyclerview.onitem touchlistener(...). Then consume that event in your fragment. As you will get item position inside touchlistener callback, you can take out data from your list directly from the list you passed to your adapter (Assuming you have list reference outside in your fragment.)
Oobserver pattern.
Define a functional interface (one callback method with required parameters of the data you want to pass) implement inside your fragment. Send its reference with the constructor of adapter. Then Store reference in a interface type variable inside adapter. Write click listener on card. And on the card click, invoke method using interface type variable.

Intents can be used to send data to new activities but not fragments You'd have to use the Fragment Manager and attach a bundle to it to send data. You can refer to the documentation here on how to do so:
https://developer.android.com/training/basics/fragments/communicating#Deliver
To handle click on cards, you can create a listener when you create PostDataAdapter. Refer to the following link for a simple example:
https://stackoverflow.com/a/40584425/4260853

for adding click item for a Cardview, you can find the Cardview in MyViewHolder class by id and in onBindViewHolder set a click listerner for it like the following
#Override
public void onBindViewHolder(MyViewHolder holder, int position) {
holder.vPostCardView.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//write your codes here
}
});
}
if you have an intent that you want to send it's data to a fragment, you can get the intent data and send them with bundle to your fragment. for example do something like the following.
Bundle bundle = new Bundle();
bundle.putString("your_key",intent.getStringExtra("your_item_key_in_intent"));
and after that send bundle to your fragment with
fragment.setArguments(bundle);

Remove fragment from backstack in nested fragments android

I have a MainActivity in which I have Added a Fragment ==> BenefitsFragment
in BenefintsFragment there is a RelativeLayout
<RelativeLayout
android:visibility="gone"
android:background="#android:color/white"
android:id="#+id/benefitContainer"
android:layout_width="match_parent"
android:layout_height="match_parent">
</RelativeLayout>
I am adding another fragment like
browseBtn.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
RelativeLayout mLayout = (RelativeLayout) view.findViewById(R.id.benefitContainer);
mLayout.setVisibility(View.VISIBLE);
getChildFragmentManager().beginTransaction()
.add(R.id.benefitContainer, new ConfirmPinFragment()).commitNow();
}
});
In my new ConfirmPinFragment I am trying to go back to old BenefitsFragment as
backBtn.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
getChildFragmentManager().popBackStack();
}
});
However this popBackStack not working, if i try to remove using
getChildFragmentManager().beginTransaction().remove(ConfirmPinFragment.this).commitNow();
It crashes saying
java.lang.IllegalStateException: FragmentManager is already executing transactions

There are two things you need to do for this to work. But first of all there is really no need for commitNow(). The first thing you need to do is to add the fragment you want to go back to into the back stack during the transaction:
browseBtn.setOnClickListener(new View.OnClickListener()
{
#Override
public void onClick(View v)
{
RelativeLayout mLayout = (RelativeLayout) view.findViewById(R.id.benefitContainer);
mLayout.setVisibility(View.VISIBLE);
getChildFragmentManager().beginTransaction()
.add(R.id.benefitContainer, new ConfirmPinFragment())
.addToBackStack("benefits fragment").commit();
}
});
and when you go back use the getFragmentManager() instead of getChildFragmentManager() because you actually want the fragment manager that holds this fragment. Child fragment manager is the manager that manages the fragments inside this fragment.
backBtn.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
getFragmentManager().popBackStack();
}
});
Hope this helps.

You add to the back state from the FragmentTransaction and remove from the backstack using FragmentManager pop methods:
FragmentManager manager = getActivity().getSupportFragmentManager();
FragmentTransaction trans = manager.beginTransaction();
trans.remove(myFrag);
trans.commit();
manager.popBackStack();

Be careful when using commitNow(), the fragment that you add won't be added into backstack. See this answer and this blog post for more info.
If you want to use backstack you should use commit() with addToBackStack() instead of commitNow()
The main reason why commitNow() is not adding into backstack is commitNow() will execute the transaction synchronously, if it'll added into backstack the transaction can broke the backstack order if there are another pending asynchronous transactions.

Using Kotlin and fragment-ktx using this one:
In your gradle:
implementation "androidx.fragment:fragment-ktx:$androidXFragmentKtxVersion"
In your Fragment
childFragmentManager
.findFragmentByTag(YOUR_TAG)?.let { fragment ->
childFragmentManager.commit(allowStateLoss = true) {
remove(fragment)
}
}
If you are not using childFragmentManager use requireActivity().supportFragmentManager instead
requireActivity().supportFragmentManage
.findFragmentByTag(YOUR_TAG)?.let { fragment ->
requireActivity().supportFragmentManage.commit(allowStateLoss = true) {
remove(fragment)
}
}

How to update custom RecyclerView from FragmentDialog?

I have an Activity A with a fragment frag2. Inside the fragment I have a RecyclerView and Adapter to show a list of custom class objects. Adding objects to the adapter is handled programmatically. I have a button inside TwoFragment that opens a FragmentDialog. I'd like to add an object to my Adapter by confirming this dialog, but it seems that the adapter is null when called from the FragmentDialog.
The same adapter is not null, and works if I call it from the fragment OnClick.
Moreover the adapter is null only after screen rotation, it works fine before rotating.
To communicate between the two Fragments I implement a communicator class in activity A.
Activity A
public void respond(String type) {
frag2.addSupport(type);
}
frag2
public RecyclerView rv;
public ArrayList<support> supports;
public myAdapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
supports = new ArrayList<>();
adapter = new myAdapter(supports);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View layout = inflater.inflate( R.layout.fragment_two, container, false);
layout.setId(R.id.frag2);
if (savedInstanceState!=null)
{
supports = savedInstanceState.getParcelableArrayList("supports");
}
rv = (RecyclerView) layout.findViewById(R.id.rv);
adapter = new myAdapter(supports);
rv.setAdapter(myAdapter);
rv.setLayoutManager(new LinearLayoutManager(getActivity()));
rv.setItemAnimator(new DefaultItemAnimator());
#Override
public void onClick(View v) {
int id = v.getId();
switch (id){
case R.id.button1:
addSupport(type); // THIS WORKS ALWAYS, even after screen rotate
break;
case R.id.button2:
showDialog();
break;
}
}
public void showDialog(){
FragmentManager manager = getFragmentManager();
myDialog dialog = new myDialog();
dialog.show(manager, "dialog");
}
public void addSupport(String type){
adapter.addItem(new support(type)); // this line gives null pointer on adapter, but only if called after screen rotate and only if called from the dialog
}
dialog
communicator comm;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.dialog, null);
comm = (myCommunicator) getActivity();
create = (Button) view.findViewById(R.id.button_ok);
create.setOnClickListener(this);
return view;
}
#Override
public void onClick(View v) {
if(v.getId()==R.id.button_ok)
{
// some controls to set type
comm.respond(type)
dismiss();
}
else {
dismiss();
}
myAdapter
public class myAdapter extends RecyclerView.Adapter<myAdapter.VH> {
private LayoutInflater inflater;
private ArrayList<support> data = new ArrayList<>();
// settings for viewholder
public myAdapter (ArrayList<support> data)
{
this.data=data;
}
public void addItem(support dataObj) {
data.add(dataObj);
notifyItemInserted(data.size());
}
}
logcat
FATAL EXCEPTION: main
java.lang.NullPointerException: Attempt to invoke virtual method 'myAdapter.addItem(myObject)' on a null object reference
I hope there are no mistakes, I shortened the code for better understanding. Keep in mind that everything works if I never rotate the screen.
I'm a beginner with android and I'm stuck with this for several days now. Please, help.

To understand the problem, it's as you say:
.. everything works if I never rotate the screen
So firstly to understand what happens on rotation, this is a quote from the Android Developer website:
Caution: Your activity will be destroyed and recreated each time the user rotates the screen. When the screen changes orientation, the system destroys and recreates the foreground activity because the screen configuration has changed and your activity might need to load alternative resources (such as the layout).
Ok, now to understand the error:
FATAL EXCEPTION: main
java.lang.NullPointerException: Attempt to invoke virtual method 'myAdapter.addItem(myObject)' on a null object reference
Essentially, in your dialog class, you have created a strong dependency by declaring :
comm = (myCommunicator) getActivity();
because comm references objects which would have been destroyed on rotation, hence the NullPointerException.
To further understand runtime changes, such as orientation changes, I'd recommend going through Handling Runtime Changes.
Update
Thank you for your answer, what would you recommend instead of comm = (myCommunicator) getActivity(); ?
The solution comes in 3 parts:
Make sure the onCreate of Activity A has the following:
#Override
public void onCreate(Bundle savedInstanceState) {
......
// find the retained fragment on activity restarts
FragmentManager fm = getFragmentManager();
frag2 = (Frag2) fm.findFragmentByTag(“frag2”);
// create frag2 only for the first time
if (frag2 == null) {
// add the fragment
frag2 = new Frag2();
fm.beginTransaction().add(frag2 , “frag2”).commit();
}
......
}
Add setRetainInstance(true) to the onCreate of frag2.
Remove the implicit referencing i.e. comm = (myCommunicator) getActivity();, and implement something more loosely coupled for dialog.
dialog
public interface Communicator {
void respond(String type);
}
Communicator comm;
....
public void addCommunicator(Communicator communicator) {
comm = communicator;
}
public void removeCommunicator() {
comm = null;
}
#Override
public void onClick(View v) {
if((v.getId()==R.id.button_ok) && (comm!=null))
{
// some controls to set type
comm.respond(type);
}
// Regardless of what button is pressed, the dialog will dismiss
dismiss();
}
This allows you do the following in frag2 (or any other class for that matter):
frag2
<pre><code>
public class Frag2 extends Fragment implements dialog.Communicator {
........
public void showDialog() {
FragmentManager manager = getFragmentManager();
myDialog dialog = new myDialog();
dialog.addCommunicator(this);
dialog.show(manager, "dialog");
}
#Override
public void respond(String type){
adapter.addItem(new support(type));
}
}

Using Fragments and Creating "Starting Page"

I'm new in Android App developing via Java. I'm using Eclipse. If I create an Activity, Eclipse automatically generates a Placeholderfragment Class and Fragment.xml. Can I disable this function? Or is it not advisable to do that? I delete those files because I find it more complicated to use than just write in one xml file at the moment.
Second question is how do I implement a "starting Page" for my App? For example some sort of a logopage which automatically disables after a few seconds and switches to a new activity. Create a separate Activity for it or do I use something else?

Actually you need two activities, one startup Activity which is used to show your logo or some guide,the other is a MainActivity which should be started by the startUp Activity.

In short You can do something like this:
public class MainActivity extends FragmentActivity {
Fragment fragment;
String className;
#Override
protected void onCreate(Bundle savedInstanceState) {
Log.d("MainActivity", "onCreate");
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
//Store the name of the class
className=MainActivity.class.getSimpleName();
//First fragment should be mounted on oncreate of main activity
if (savedInstanceState == null) {
/*fragment=FragmentOne.newInstance();
getSupportFragmentManager().beginTransaction().replace(R.id.container, fragment).addToBackStack(className).commit();
*/
Fragment newFragment = FragmentOne.newInstance();
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
ft.replace(R.id.container, newFragment).addToBackStack(null).commit();
Log.d("FRAGMENT-A", "fragment added to backstack");
}
}
}
FragmentOne.java
public class FragmentOne extends Fragment{
String className;
public static FragmentOne newInstance(){
Log.d("FragmentOne", "newInstance");
FragmentOne fragment = new FragmentOne();
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.d("FragmentOne", "onCreateView");
View view=inflater.inflate(R.layout.fragment_one, container, false);
//Store the name of the class
className=FragmentOne.class.getSimpleName();
return view;
}
}
Let me know if you need any more info

Well, in a Single Activity setup, the way I did this was the following:
public class SplashFragment extends Fragment implements View.OnClickListener
{
private volatile boolean showSplash = true;
private ReplaceWith activity_replaceWith;
private Button splashButton;
public SplashFragment()
{
super();
}
#Override
public void onAttach(Activity activity)
{
super.onAttach(activity);
try
{
activity_replaceWith = (ReplaceWith) activity;
}
catch (ClassCastException e)
{
Log.e(getClass().getSimpleName(), "Activity of " + getClass().getSimpleName() + "must implement ReplaceWith interface!", e);
throw e;
}
startSwitcherThread();
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View rootView = inflater.inflate(R.layout.fragment_splash, container, false);
splashButton = (Button) rootView.findViewById(R.id.fragment_splash_button);
splashButton.setOnClickListener(this);
return rootView;
}
public void startSwitcherThread()
{
Thread splashDelay = new Thread()
{
#Override
public void run()
{
try
{
long millis = 0;
while (showSplash && millis < 4000)
{
sleep(100);
millis += 100;
}
showSplash = false;
switchToFirstScreen();
}
catch (Exception e)
{
e.printStackTrace();
}
}
};
splashDelay.start();
}
private void switchToFirstScreen()
{
activity_replaceWith.replaceWith(new FirstFragment());
}
#Override
public void onClick(View v)
{
if(v == splashButton)
{
if(showSplash == false)
{
switchToFirstScreen();
}
}
};
}
Where the ReplaceWith interface is the following:
import android.support.v4.app.Fragment;
public interface ReplaceWith
{
public void replaceWith(Fragment fragment);
}
And the replace function is implemented like so:
#Override
public void replaceWith(Fragment fragment)
{
getSupportFragmentManager()
.beginTransaction().replace(R.id.fragment_container, fragment)
.addToBackStack(null)
.commit();
}
Now, most people will say this is not a good approach if you're using multiple activities, and/or using multiple orientations and aren't just simply displaying a single Fragment in a single Activity no matter what. And they are completely right in saying so.
Multiple orientations would require the Activity to be responsible for knowing what is the "next" Fragment at a given replace call, and where to place it (which container, or to start it in a new Activity). So this is a valid approach only if you are certain that you only have one container and there is one Fragment shown at a given time.
So basically, if this does not apply to you, then you need to utilize the same approach (make a specific delay before you replace the current Fragment or Activity with another one, this specific code allows you that once the splash has been shown once, then clicking the button will automatically take you to the next screen - typical game splash setup, really), but use activity callbacks specific to the Fragment in order to swap one out for the other.
A Fragment setup I recommend and isn't relying on this special case can be seen here: Simple Android Project or its equivalent on Code Review: Fragment Start-Up Project

Transferring multiple strings between Fragments of the same activity with tags

I am having trouble figuring out how to share data between my two fragments which are hosted on the same activity.
The objective:
I want to transfer string from the the selected position of a spinner and an image url string from a selected list view position from fragment A to fragment B.
The Attempt:
I read the fragments doc on this problem here http://developer.android.com/guide/components/fragments.html#CommunicatingWithActivity
And went ahead an created the following Interface to use betweeen the Fragments and the Host Activity.
public interface OnSelectionListener {
public void OnSelectionListener(String img, String comments );
}
Then I proceeded to implement it in my fragment A's onCreateView method like so:
postList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
#Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
ListData link = data.get(position);
String permalink = link.getComments();
String largeImg = link.getImageUrl();
Fragment newFragment = new DetailsView();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
// Commit the transaction
transaction.commit();
//pass data to host activity
selectionListener.OnSelectionListener(permalink,largeImg);
}
});
And also in the onAttach method
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
selectionListener = (OnSelectionListener)getActivity();
} catch (ClassCastException e) {
throw new ClassCastException(activity.toString() + " must implement onSelectionListener");
}
}
In the Host activity I implemented the interface I wrote and overrided the method like so:
#Override
public void OnSelectionListener(String img, String comments) {
DetailsView detailsView = new DetailsView();
DetailsView dView = (DetailsView)getSupportFragmentManager().findFragmentByTag(detailsView.getCustomTag());
dView.setInformation(img, comments);
}
In Fragment B I set a "tag" the following way
private String tag;
public void setCustomTag(String tag)
{
this.tag = tag;
}
public String getCustomTag()
{
return tag;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setCustomTag("DETAILS_VIEW");
And my thinking is that that the information can be passed to Fragment B by calling this method from the host activity
void setInformation (String info, String img){
RedditDetailsTask detailsTask = new RedditDetailsTask(null,DetailsView.this);
detailsTask.execute(info);
setDrawable(img);
}
What I need:
I want to know how to properly use tags to get this to work, I dont have any fragment id's declared in my xml and rather opted to exchange fragments in a fragment_container.
I also am not sure if this is a good way to pass multiple strings between fragments. I am a newbie programmer so I know my logic probably looks pretty embarrassing but I am trying to do my best learn to do this right. I would appreciate it if you more senior developers can point me in the right direction for doing this.

You don't need to use tags. Take a look at this example. The Activity implements an interface that allows you to talk from Fragment1 back to the Activity, the Activity then relays the information into Fragment2.
I've left out all the android stuff about FragmentManager etc.
interface FragmentListener {
void onTalk(String s1);
}
public class MyActivity extends Activity implements FragmentListener {
Fragment2 fragment2;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_my);
// Find fragment2 and init
}
#Override
public void onTalk(String s1) {
fragment2.onListen(s1);
}
private static class Fragment1 extends Fragment {
private FragmentListener communication;
#Override
public void onAttach(Activity activity) {
super.onAttach(activity);
communication = (FragmentListener) activity;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_one, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
// or in an onClick listener
communication.onTalk("blah blah");
}
}
private static class Fragment2 extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_two, container, false);
}
public void onListen(String s1) {
Log.d("TADA", s1);
}
}
}

My approach would be, when you get the callback in activity through the OnSelectionListener interface, I would create the Fragment B object and set arguments to it as follows:
#Override
public void OnSelectionListener(String img, String comments) {
DetailsView detailsView = new DetailsView();
Bundle args=new Bundle();
args.putString("img",img);
args.putString("comments",comments);
detailsView.setArguments(args);
//code here to replace the fragment A with fragment B
}
Then in Fragment B's onCreate method you can retrieve the values as follows:
#Override
public void onCreate(Bundle savedInstanceState) {
Bundle args=getArguments();
String img=args.getString("img");
String comments=args.getString("comments");
//do whatever you want to do with the varaibles
}

You could try to make two public static String's in your B fragment.
it Would look like something like this
public static String img;
public static String comment;
The you set the variables before making the transaction to fragment B
FragmentTransaction transaction = getFragmentManager().beginTransaction();
// Replace whatever is in the fragment_container view with this fragment,
// and add the transaction to the back stack
transaction.replace(R.id.fragment_container, newFragment);
transaction.addToBackStack(null);
SecondFragment.img = new String("imgString"); //Making a new string so incase you change the string in bfragment, the values wont change in here
SecondFragment.comment = new String("comment");
// Commit the transaction
transaction.commit();
Then in the onStop(), or onDestroy() - depending on when you want the variables to be null, check this - you set the the static variables to null, so they dont take memory space
public void onDestroy(){
super.onDestroy();
img = null;
comment = null;
}