There is an activity containing a Button and a LinerLayout which is the container of Fragment. The layout of Fragment only contains a TextView. I want to send a string to fragment from activity, but what fragment received is null. Why?
xml of Activity:
<Button
android:id="#+id/load"
android:layout_width="match_parent"
android:layout_height="80dp"
android:text="load" />
<!--the container of fragment-->
<LinearLayout
android:id="#+id/container"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal" />
xml of Fragment:
<TextView
android:id="#+id/fragment_text"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
Java code of Activity:
public class DynamicFragmentActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dynamic_fragment);
findViewById(R.id.load).setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
//create fragment and set data
MyFragment myFragment = new MyFragment();
Bundle bundle = new Bundle();
bundle.putString("text", "demo");
myFragment.setArguments(bundle);
//commit
FragmentManager fragmentManager = getFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
fragmentTransaction.add(R.id.container, myFragment);
fragmentTransaction.commit();
}
});
}
}
Java code of Fragment:
public class MyFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.myfragment, container, false);
TextView textView = (TextView) view.findViewById(R.id.fragment_text);
//receive data
String text = getArguments().getBundle("text")+"";
textView.setText(text);
return view;
}
}
Try this , Hope it helps ...........
public class MyFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.myfragment, container, false);
TextView textView = (TextView) view.findViewById(R.id.fragment_text);
//change getBundle() to getString()
String text = getArguments().getString("text")+"";
textView.setText(text);
return view;
}
}
What you are doing now is get a Bundle called text and what you really want is get a string in the bundle:
Bundle arg = getArguments();
String txt = arg.getString("text");
Related
Theoretically, lets say i have two classes with corresponding XML files - Activity and Frag
Activity.java
public class Activity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
Fragment fragment = new Frag();
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
ft.replace(R.id.fragmentArea, fragment);
ft.commit();
}
}
Frag.java
public class Frag extends Fragment {
private TextView txtView;
public Frag() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_, container, false);
txtView = view.findViewById(R.id.textView);
return view;
}
public void setTextView(String str) {
txtView.setText(str);
}
}
activity xml
<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout
xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.eksamen.chris.eksempelfragment.Activity">
<LinearLayout
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:orientation="horizontal"
android:id="#+id/fragmentArea">
</LinearLayout>
</android.support.constraint.ConstraintLayout>
Fragment xml
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
tools:context="com.eksamen.chris.eksempelfragment.Frag">
<!-- TODO: Update blank fragment layout -->
<TextView
android:layout_width="match_parent"
android:layout_height="match_parent"
android:text="Fragment"
android:id="#+id/textView"/>
</FrameLayout>
As you can see, i have the method setTextView() in my Frag class. Obviously enough, what i would like to do is to call that method from my Activity class.
I have tried grasping this for some hours now, and i really cannot figure out a way to do this. Every example/tutorial out there makes my app crash.
Could someone explain to me how this works, taken the example we have in hand into consideration? Or maybe there is a better way to provide the fragment with data from my activity?
I'd be grateful!
Edit: awful indentation, had some issues, trying to fix.
In order to pass data from Activity to Fragment , you have to use :
Bundle
which is a KEY VALUE data structure for passing values between fragments and activity so at your onCreate() in Activity class will be
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
String str = "your_string_here";
// 1 -
Bundle bundle = new Bundle();
// 2 -
bundle.putString("KEY", str);
Fragment fragment = new Frag();
FragmentManager fm = getFragmentManager();
FragmentTransaction ft = fm.beginTransaction();
// 3 -
fragment.setArguments(bundle);
ft.replace(R.id.fragmentArea, fragment);
ft.commit(); }
and at your fragment
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_, container, false);
txtView = view.findViewById(R.id.textView);
// 4 - NOTE : Should hould the same key at the Activity class :
String str = getArguments().getString("KEY");
setTextView(str);
return view;
}
Trying to add Fragment to my Activity, but it isn't showing up.
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WeatherFragment mainFragment = new WeatherFragment();
getFragmentManager()
.beginTransaction()
.add(R.id.main_weather_container, mainFragment)
.commit();
}
}
And there is my fragment:
public class WeatherFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
boolean isAttachedToParent = false;
View inflatedView = inflater.inflate(R.layout.main_weather_fragment, container, isAttachedToParent);
return inflatedView;
}
}
R.id.main_weather_container - FrameLayout in my MainActivity.
R.layout.main_weather_fragment - Fragment's layout
What am i doing wrong?
I've tried to use FragmentActivity + v4 support fragment and fragmentSupportManager, but it didn't make any difference.
MainActivity xml:
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<FrameLayout
android:id="#+id/main_weather_container"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:padding="#dimen/padding_16_dp" />
<android.support.v7.widget.RecyclerView
android:id="#+id/words_recycler_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="3" />
</LinearLayout>
UPDATED: The problem wasn't in fragment transaction or whatever, i've used tools: namespace that's why fragment wasn't displayed. Sorry about that :(
try this way .in your activity call fragment
Fragment fragment = Video_fragment.newInstance();
FragmentTransaction transaction = getSupportFragmentManager().beginTransaction();
transaction.replace(R.id.framecontainer, fragment).commit();
in fragment class.
public class Video_fragment extends Fragment{
View view;
public static Fragment newInstance() {
Video_fragment fragment = new Video_fragment();
return fragment;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
view= inflater.inflate(R.layout.video_frag, container, false);
return view;
}
}
Create a instance of Fragment in WeatherFragment:
public static WeatherFragment newInstance() {
Bundle args = new Bundle();
WeatherFragment weatherFragment = new WeatherFragment();
weatherFragment.setArguments(args);
return weatherFragment;
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.fragment_layout, container, false);
}
Inside your Activity in MainActivity :
#Override
protected void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
WeatherFragment weatherFragment = WeatherFragment.newInstance();
getSupportFragmentManager()
.beginTransaction()
.replace(R.id.flContainerId, weatherFragment)
.commit();
}
Your layout file will be:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:id="#+id/flContainerId"/>
public class WeatherFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View inflatedView = inflater.inflate(R.layout.main_weather_fragment, null, false);
return inflatedView;
}
}
As I can see, you are using AppCompatActivity but using getFragmentManager.
With AppCompatActivity you will need to use getSupportFragmentManager() rather than getFragmentManager()
public class MainActivity extends AppCompatActivity {
private static final String TAG = MainActivity.class.getSimpleName();
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
WeatherFragment mainFragment = new WeatherFragment();
getSupportFragmentManager()
.beginTransaction()
.add(R.id.main_weather_container, mainFragment)
.commit();
}
}
Your WeatherFragment should be extend android.support.v4.app.Fragment;
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:weightSum="4"
android:orientation="vertical">
<FrameLayout
android:id="#+id/main_weather_container"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:padding="#dimen/padding_16_dp" />
<android.support.v7.widget.RecyclerView
android:id="#+id/words_recycler_view"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="3" />
</LinearLayout>
Added WeightSum in the parent Layout.
I am trying to get the data from previous Activity to a Fragment. I am able to get the data without Fragment but, when I put the code inside Fragment, it doesn't work. My Fragment is inside description class. Here is my code:
This is how I am sending data from previous Activity:
TextView textView = (TextView) view.findViewById(R.id.txt_name);
String text = textView.getText().toString();
if(text.equals("ADA")) {
intent = new Intent(view.getContext(), description.class);
intent.putExtra("ADA", text);
startActivity(intent);
}
This is how I am getting it inside Fragment:
public static class DummyFragment extends Fragment {
int color;
TextView mTextview;
public DummyFragment() {
}
#SuppressLint("ValidFragment")
public DummyFragment(int color) {
this.color = color;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.dummy_fragment, container, false);
final FrameLayout frameLayout = (FrameLayout) view.findViewById(R.id.dummyfrag_bg);
frameLayout.setBackgroundColor(color);
RecyclerView recyclerView = (RecyclerView) view.findViewById(R.id.dummyfrag_scrollableview);
LinearLayoutManager linearLayoutManager = new LinearLayoutManager(getActivity().getBaseContext());
recyclerView.setLayoutManager(linearLayoutManager);
recyclerView.setHasFixedSize(true);
mTextview = (TextView) view.findViewById(R.id.textView1);
mTextview.setText(getActivity().getIntent().getStringExtra("ADA"));
return view;
}
}
This is my xml code:
<?xml version="1.0" encoding="utf-8"?>
<FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:id="#+id/dummyfrag_bg"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="#color/bg_light">
<android.support.v7.widget.RecyclerView
android:id="#+id/dummyfrag_scrollableview"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:clipToPadding="false"
android:paddingBottom="#dimen/activity_horizontal_margin"
android:paddingTop="#dimen/activity_horizontal_margin" />
</FrameLayout>
And:
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:tools="http://schemas.android.com/tools"
android:layout_width="match_parent"
android:layout_height="match_parent">
<TextView
android:id="#+id/textView1"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_centerHorizontal="true"
android:layout_marginTop="42dp"
android:textAppearance="?android:attr/textAppearanceLarge" />
</RelativeLayout>
TextView textView = (TextView) view.findViewById(R.id.txt_name);
String text = textView.getText().toString();
if(text.equals("ADA")) {
DummyFragment fragment = new DummyFragment();
Bundle bundle = new Bundle();
bundle.putString("ADA",text);
fragment.setArguments(bundle);
getSupportFragmentManager()
.beginTransaction()
.replace(fragment,R.id.layout)
.addTobackStack(null)
.commit();
}
then in your fragment
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.dummy_fragment, container, false);
String text = getArguments().getString("ADA");
}
EDIT
Explaination
1) fragmentTransaction.replace(int containerViewId, Fragment fragment, String tag)
Replace an existing fragment that was added to a container. This is essentially the same as calling remove(Fragment) for all currently added fragments that were added with the same containerViewId and then add(int, Fragment, String) with the same arguments given here.
2) fragmentTransaction.add(int containerViewId, Fragment fragment, String tag)
Add a fragment to the activity state. This fragment may optionally also have its view (if Fragment.onCreateView returns non-null) into a container view of the activity.
Use SharedPreferences to store the text. Do this in the Activity before loading fragment
SharedPreferences sharedPreferences = getSharedPreferences("TextHolder", 0);
SharedPreferences.Editor editor = sharedPreferences.edit();
editor.putString("ADA", textView.getText().toString()).apply();
Inside the Fragment get the text from SharedPreferences like this
String textHolder = getActivity().getSharedPreferences("TextHolder", 0).getString("ADA", "");
Now set the textHolder String to the TextView of your choice inside the Fragment
I am sending data from one fragment to another, using interface. This works absolutely fine. Now I am trying to use onSaveInstanceState() to save the value in
a Fragment and retrieving in onCreate(). however i'm getting null in Bundle of onCreate(). P.S. everything works fine when i set the Fragment directly into the activity layout in xml. but when i set the fragment through java code into the activity, the onSaveInstanceState is failing. It is not saving the last known value. Please help. Pasting the code below. You can try it out to know the exact issue.
Fragment_A :
public class Fragment_A extends Fragment implements View.OnClickListener {
Button btnAdd;
int counter = 0;
Communicator comm;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
if(savedInstanceState != null){
counter = savedInstanceState.getInt("counter", 0);
}
}
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_a, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
comm = (Communicator) getActivity();
btnAdd = (Button) getActivity().findViewById(R.id.btnAdd);
btnAdd.setOnClickListener(this);
}
#Override
public void onSaveInstanceState(Bundle outState) {
super.onSaveInstanceState(outState);
outState.putInt("counter", counter);
}
#Override
public void onClick(View v) {
counter++;
comm.sendData(counter);
}
}
interface Communicator{
void sendData(int i);
}
=====
Activity :
public class Activity_InterComm extends Activity implements Communicator{
FragmentManager manager;
FragmentTransaction transaction;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_intercomm);
Fragment_A fragment_1 = new Fragment_A();
Fragment_B fragment_2 = new Fragment_B();
manager = getFragmentManager();
transaction = manager.beginTransaction();
transaction.add(R.id.frag_a, fragment_1, "Frag1");
transaction.add(R.id.frag_b, fragment_2, "Frag2");
transaction.commit();
}
#Override
public void sendData(int i) {
manager = getFragmentManager();
Fragment_B fragment_b = (Fragment_B) manager.findFragmentById(R.id.frag_b);
fragment_b.setData("Button has been clicked " + i + " times");
}
}
=====
Fragment_B :
public class Fragment_B extends Fragment {
TextView txtMessage;
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_b, container, false);
return view;
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
txtMessage = (TextView) getActivity().findViewById(R.id.txtMessage);
}
public void setData(String message){
txtMessage.setText(message);
}
}
activity_intercomm.xml :
<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="vertical">
<!--<fragment
android:id="#+id/frag_a"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:name="android.learning.com.fragintercomm.Fragment_A"/>
<fragment
android:id="#+id/frag_b"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_weight="1"
android:name="android.learning.com.fragintercomm.Fragment_B"/>-->
<LinearLayout
android:id="#+id/frag_a"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:background="#color/colorAccent"
android:orientation="vertical"/>
<LinearLayout
android:id="#+id/frag_b"
android:layout_width="match_parent"
android:layout_height="0dp"
android:layout_marginBottom="8dp"
android:layout_weight="1"
android:background="#color/colorPrimaryDark"
android:orientation="vertical"/>
</LinearLayout>
the soluion I found was using getView() instead of getActivity() while initializing the button in Fragment_A. use btnAdd = (Button) getView().findViewById(R.id.btnAdd); instead of btnAdd = (Button) getActivity().findViewById(R.id.btnAdd);.
However, you can't use getView() in Fragment_B. The Textview freezes and, onSaveInstanceStat() doesn't work. Please suggest a solution.
i want add a fragment inside another one dynamically .
the outer fragment is a DialogFragment :
public class MapFragmentDialog extends DialogFragment implements OnMapClickListener, OnMapLongClickListener,
OnMarkerDragListener {
FragmentManager fmanager;
Fragment fragment;
SupportMapFragment supportmapfragment;
public static MapFragmentDialog newInstance() {
MapFragmentDialog f = new MapFragmentDialog();
return f;
}
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View v = inflater.inflate(R.layout.map_fragment, container, false);
// *********** add myMapFragment
FragmentManager fragmentManager = getActivity().getSupportFragmentManager();
FragmentTransaction fragmentTransaction = fragmentManager.beginTransaction();
// add a fragment
MyMapFragment myFragment = new MyMapFragment();
fragmentTransaction.add(R.id.myfragment, myFragment);
fragmentTransaction.commit();
myMap = ((SupportMapFragment)getActivity().getSupportFragmentManager().findFragmentById(R.id.myMap)).getMap();
return v;
}
the map_fragment layout is like this :
<TextView
android:id="#+id/txtHelp"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:gravity="center_vertical"
android:paddingBottom="6dip"
android:textAlignment="center"
android:textAppearance="?android:attr/textAppearanceSmall"
android:textSize="12sp" />
<FrameLayout
android:id="#+id/myfragment"
android:layout_width="0px"
android:layout_height="wrap_content" />
my inner fragment MyMapFragment :
public class MyMapFragment extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View myFragmentView = inflater.inflate(R.layout.my_map_fragment, container, false);
return myFragmentView;
}}
the my_map_fragment layout contain :
<fragment
android:id="#+id/myMap"
android:layout_width="match_parent"
android:layout_height="300dp"
class="com.google.android.gms.maps.SupportMapFragment" />
i get an exception on getting the map fragment on my DialogFragment , a NullPointerException at this line
myMap = ((SupportMapFragment)getActivity().getSupportFragmentManager().findFragmentById(R.id.myMap)).getMap();
I remember seeing something about fragments in fragments working only dynamically and not by placing them XML. I think Abd El-Rahman El-Tama has the correct idea of using a frameLayout nstead of specifying a fragment directly
To change the Fragments dynamically all what you need is
1) A FrameLayout in your Layout as following:
<FrameLayout
android:id="#+id/fragment"
android:layout_width="wrap_content"
android:layout_height="wrap_content" />
2) Initialize the FrameLayout into your activity as following:-
FrameLayout fragment = (FrameLayout) findViewById(R.id.fragment);
3) Start Fragment transaction as following:
getSupportFragmentManager().beginTransaction().replace(R.id.fragment, new MyFragment()).commit();
Or
FragmentManager fragMan = new FragmentManager();
fragMan.beginTransaction ();
fragMan.replace (R.id.fragment);
fragMan.commit ();