Develop Reference

how to intent from Fragmet to Fragment with his parent?

Fragment1 have a different parent with Fragment2, actually i want to intent in Fragment2 with his parent.
Fragment2 fragment = new Fragment2().getParentFragment();
fragment.setArguments(bundle);
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.containerView,fragment);
ft.commit();

you must pass data to secondActivity by intent and then use setData method to pass data to fragment. Note you must do this in the onCreateView function in the fragment. Like below code:
public void setData(Data data){
this.data = data;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState){
View rootView = inflater.inflate(R.layout.fragment_layout,container,false);
// use data here
// also use view components(like buttons) here
return rootView;
}

Android relationships between fragments

I'm using some fragments programmatically in activity. There is one button in my first fragment and when i click to this button, it replaces to second fragment.My second fragment's background is 90% transparent, and when it starts, i can see button which is situated in first fragment, and it also works. I want to stop or do something, because i dont want to see first fragment features and use it.
First Fragment
public class RegistrationFirstFragment extends Fragment {
RegistrationSecondFragment rf;
ImageButton btnNewUser,btnNewAgent;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
//return super.onCreateView(inflater, container, savedInstanceState);
View v =inflater.inflate(R.layout.fragment_registration_first,container,false);
rf = new RegistrationSecondFragment();
btnNewUser = (ImageButton)v.findViewById(R.id.btnNewUserRegistrationFirstFragment);
btnNewAgent = (ImageButton)v.findViewById(R.id.btnNewAgentRegistrationFirstFragment);
btnNewUser.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
Toast.makeText(getActivity(), "Transaction completed succesfully", Toast.LENGTH_LONG).show();
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.flRegistrationFirst, rf);
ft.commit();
}
});
return v;
}
}
Second Fragment
public class RegistrationSecondFragment extends Fragment {
RegistrationFirstFragment rtl;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rtl = new RegistrationFirstFragment();
//return super.onCreateView(inflater, container, savedInstanceState);
View v =inflater.inflate(R.layout.fragment_registration_second,container,false);
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
// ft.replace(R.id.flRegistrationFirst, rf);
ft.remove(rtl);
ft.commit();
return v;
}
}
Main Activity
public class RegistrationActivity extends AppCompatActivity{
RegistrationFirstFragment fr;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_registration);
fr = new RegistrationFirstFragment();
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.add(R.id.flRegistrationFragment,fr);
ft.commit();
}
}

You can put
FragmentManager fragmentManager = getFragmentManager();
fragmentManager.beginTransaction().replace(R.id.content_frame, fragment).commit();
(the parameter fragment would be an instance of your second fragment)
into your onClick(View view){...} method to change the fragment instead of adding it.
Next time code for understanding your problem btw ;)

Add to fragment layout android:clickable="true". Int his way fragment will catch event so the click will not be caught by "main fragment".
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:clickable="true" />

Give android:clickable="true" for Second Fragment root layout parent, when ever fragment opens It catches the click event of root and ignored previous click events.
Second One: If u use replace Fragment it's better than add fragment.
getActivity().getSupportFragmentManager().beginTransaction().replace
(R.id.YOUR_CONTAINER, 'FragmentObject').addToBackStack("TAG").commitAllowingStateLoss();

nullpointer running method of fragment from activity when using views

My Fragment
public class CustomFrag extends Fragment {
private Button btn;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.button_fragment, container, false);
btn = (Button)view.findViewById(R.id.button1);
return view;
}
public void sendItem(String item) {
btn.setText(item);
}
}
And in my activity
public void loadFragment(String data) {
// Load up new fragment
Fragment fragment = new CustomFrag();
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
transaction.add(R.id.contentFragment, fragment, "custFrag");
transaction.addToBackStack("custFrag");
transaction.commit();
// Required before calling fragment methods
getSupportFragmentManager().executePendingTransactions();
// Load fragment with data
CustomFrag frag = (CustomFrag) getSupportFragmentManager().findFragmentByTag("custFrag");
frag.sendItem(data);
}
I'm getting a nullpointer exception any time I attempt to use the views of my fragment. If I try to load the view inside the method as well, it will not work
i.e. inside sendItem()
btn = (Button)getView().findViewById(R.id.button1);
My layout (button_fragment) contains the button:
<Button
android:id="#+id/button1"
android:layout_width="match_parent"
android:layout_height="wrap_content" />

Because you have executed the transaction does not mean that the fragment has actually created its view. Which is why btn is still null.
To pass data from the activity to the fragment, use the argument bundle:
Fragment fragment = new CustomFrag();
Bundle args = new Bundle();
args.putString("item", data);
fragment.setArguments(args);
Then, in onCreateView:
btn = (Button)view.findViewById(R.id.button1);
btn.setText(getArguments().getString("item"));
See this Best practice for instantiating a new Android Fragment question and the first answer.

The problem here is that the fragment's layout is not drawn yet when sendItem(...) is called. Which means btn is null at that point. Instead, this is how you're supposed to do it (see http://developer.android.com/guide/components/fragments.html):
public class CustomFrag extends Fragment {
private Button btn;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.button_fragment, container, false);
btn = (Button)view.findViewById(R.id.button1);
btn.setText(getArguments.getString("item"));
return view;
}
}
And
public void loadFragment(String data) {
// Load up new fragment
Fragment fragment = new CustomFrag();
Bundle args = new Bundle();
args.putString("item", data);
fragment.setArguments(args);
FragmentManager fm = getSupportFragmentManager();
FragmentTransaction transaction = fm.beginTransaction();
transaction.add(R.id.contentFragment, fragment, "custFrag");
transaction.addToBackStack("custFrag");
transaction.commit();
// Required before calling fragment methods
getSupportFragmentManager().executePendingTransactions();
}
Edit:
njzk2 was faster, but I hope the details I gave will help you further. In any case, the link he gave explains nicely why you should do it like that.

How to move from one fragment to another fragment on click of an ImageView in Android?

I have an ImageView. I want to move from one fragment to another fragment on a click of an Imageview, the same way like we can move from one activity to another using
Intent i=new Intent(MainActivity.this,SecondActivity.class);
startActivity(i);
How can I do this? Can anyone explain to me step by step?
My codes are as follows:
mycontacts.class
public class mycontacts extends Fragment {
public mycontacts() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = super.getView(position, convertView, parent);
ImageView purple=(ImageView)v.findViewById(R.id.imageView1);
purple.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
//how to go to tasks fragment from here???
}
});
return view;
}
}
tasks.class
public class tasks extends Fragment {
public tasks() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_layout_one, container,
false);
return view;
}
}

purple.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
Fragment fragment = new tasks();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.content_frame, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();
}
});
You write the above code...there we are replacing R.id.content_frame with our fragment.

#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.fragment_profile, container, false);
notification = (ImageView)v.findViewById(R.id.notification);
notification.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View view) {
FragmentTransaction fr = getFragmentManager().beginTransaction();
fr.replace(R.id.container,new NotificationFragment());
fr.commit();
}
});
return v;
}

Add this code where you want to click and load Fragment.
Fragment fragment = new yourfragment();
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.replace(R.id.fragment_container, fragment);
fragmentTransaction.addToBackStack(null);
fragmentTransaction.commit();

When you are inside an activity and need to go to a fragment use below
getFragmentManager().beginTransaction().replace(R.id.*TO_BE_REPLACED_LAYOUT_ID*, new tasks()).commit();
But when you are inside a fragment and need to go to a fragment then just add a getActivity(). before, so it would become
getActivity().getFragmentManager().beginTransaction().replace(R.id.*TO_BE_REPLACED_LAYOUT_ID*, new tasks()).commit();
as simple as that.
The *TO_BE_REPLACED_LAYOUT_ID* can be the entire page of activity or a part of it, just make sure to put an id to the layout to be replaced. It is general practice to put the replaceable layout in a FrameLayout .

inside your onClickListener.onClick, put
getFragmentManager().beginTransaction().replace(R.id.container, new tasks()).commit();
In another word, in your mycontacts.class
public class mycontacts extends Fragment {
public mycontacts() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
final View v = super.getView(position, convertView, parent);
ImageView purple = (ImageView) v.findViewById(R.id.imageView1);
purple.setOnClickListener(new OnClickListener() {
#Override
public void onClick(View v) {
// TODO Auto-generated method stub
getFragmentManager()
.beginTransaction()
.replace(R.id.container, new tasks())
.commit();
}
});
return view;
}
}
now, remember R.id.container is the container (FrameLayout or other layouts) for the activity that calls the fragment

You can move to another fragment by using the FragmentManager transactions. Fragment can not be called like activities,. Fragments exists on the existence of activities.
You can call another fragment by writing the code below:
FragmentTransaction t = this.getFragmentManager().beginTransaction();
Fragment mFrag = new MyFragment();
t.replace(R.id.content_frame, mFrag);
t.commit();
here "R.id.content_frame" is the id of the layout on which you want to replace the fragment.
You can also add the other fragment incase of replace.

If you're looking for the Kotlin version of the above code, you can do it in this way, and you call replaceFragment(RequiredFragment()) at onClickListener or wherever you want.
private fun replaceFragment(fragment: Fragment) {
val transaction = activity!!.supportFragmentManager.beginTransaction()
transaction.replace(R.id.frame, fragment)
transaction.commit()
}

private boolean loadFragment(Fragment fragment) {
if (fragment != null) {
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.fl_fragment_container, fragment)
.commit();
return true;
}
return false;
}

in kotlin, put inside of your current running fragment button.setOnClickListener
val bpfragment = TwoFragment()
activity?.supportFragmentManager?.beginTransaction()?.replace(R.id.fragment_container, bpfragment)?.commit()

val fragment = YourFragment3()
val fm : FragmentManager= requireActivity().supportFragmentManager
val ft: FragmentTransaction = fm.beginTransaction()
ft.replace(R.id.container, fragment)
ft.commit()
(activity as MainActivity).binding.viewPager.setCurrentItem(2)

We can use this one-
purple.setOnClickListener(view1 -> {
Fragment fragment = new task();
FragmentManager manager = getFragmentManager();
FragmentTransaction transaction = manager.beginTransaction();
transaction.replace(R.id.frame, fragment);
transaction.addToBackStack(null);
transaction.commit();
});

Fragments the right way

I'm trying out some fragments right now. I've got a fragment with a button and when I click that button I switch to another fragment. Now when I push on the back button I return to the first fragment that's good. Now when I click again on that button a new fragment is started. So I always start a new fragment. I think thats not the way it needs to be done. Is there a better way to for example resume the already created fragment?
My code:
public static class PlaceholderFragment extends Fragment{
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main, container, false);
Button test = (Button)rootView.findViewById(R.id.button);
test.setOnClickListener(new OnClickListener()
{
#Override
public void onClick(View view)
{
Log.d("Test", "Button clicked.");
TestFrag newFragment = new TestFrag();
FragmentTransaction transaction = getFragmentManager().beginTransaction();
transaction.replace(R.id.container, newFragment);
transaction.addToBackStack(null);
transaction.commit();
}
});
return rootView;
}
}
public static class TestFrag extends Fragment {
public TestFrag() {
Log.d("Test","New fragment");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_main2, container, false);
return rootView;
}
}

When you use the fragment transaction you can specify a tag for the fragment
fragmentTransaction.add(R.id.main_fragment, newFragment, fragTag);
fragmentTransaction.commit();
Then later you can find a fragment by tag from the fragmentManager
newFragment = fragMan.findFragmentByTag(fragTag);
if newFragment then is null you should create the Fragment since it wasnt found by the tag

Thanks to Joakim:
fragmentTransaction.add(R.id.main_fragment, newFragment, fragTag); fragmentTransaction.commit();
Then later you can find a fragment by tag from the fragmentManager
newFragment = fragMan.findFragmentByTag(fragTag); if newFragment then is null you should create the Fragment since it wasnt found by the tag. If the tag isn't null you can just add and commit the new one.