I have an activity which receive data from other activity. This data has to be showed in a TextView in a fragment inflated in the activity. So, the code is:
public class DetailActivity extends Activity {
private int idEstablecimiento;
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment()).commit(); //Here the fragment is added to the activity
}
Bundle extras = getIntent().getExtras();
if (extras != null) {
idEstablecimiento = extras.getInt("idEstablecimiento");
}
TextView textView = (TextView) this.findViewById(R.id.nombreView); //Declared in fragmentDetail, which has been already inflated at this point, but still null
textView.setText(this.idEstablecimiento);
}
//...
//Non related stuff...
//...
public static class PlaceholderFragment extends Fragment {
private int idEstablecimiento;
public PlaceholderFragment() {
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_detail,
container, false);
return rootView;
}
}
The problem is that the textView in the onCreate() method is null, why is this happening if the fragment has been already inflated? Shouldn't I be able to access to the IU elements once the fragment has been inflated in the onCreate() method? Or if not, what is the rigth way to do access to it?
You have to find the TextView in the Fragment.
public static class PlaceholderFragment extends Fragment {
private int idEstablecimiento;
public PlaceholderFragment() {
}
public PlaceholderFragment(int idEstablecimiento) {
this.idEstablecimiento = idEstablecimiento;
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_detail,
container, false);
TextView text = rootView.findViewById(R.id.nombreView);
text.setText(idEstablecimiento);
return rootView;
}
And then you can get the text and commit it.
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_detail);
Bundle extras = getIntent().getExtras();
if (extras != null) {
idEstablecimiento = extras.getInt("idEstablecimiento");
}
if (savedInstanceState == null) {
getFragmentManager().beginTransaction()
.add(R.id.container, new PlaceholderFragment(idEstablecimiento)).commit();
}
}
Regards
Nils
If you want to get the View from a fragment layout you should use the view inside the oncreateView of the fragment and then get the textView inside the oncreate view..
example:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_detail,
container, false);
TextView textView = (TextView) rootView.this.findViewById(R.id.nombreView); //Declared in fragmentDetail, which has been already inflated at this point, but still null
textView.setText("I am here");
return rootView;
}
Related
I am learning android developing(novice).I want to add a fragment to the mainActivity with a textview and change the text. This code works perfectly:
public class Fragment1 extends Fragment {
//#Nullable
//#Override
TextView textt;
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_fragment1, container, false);
((TextView)view.findViewById(R.id.textview)).setText("some text");
return view;
}
}
But this codes invokes null pointer exception:
public class Fragment1 extends Fragment {
//#Nullable
//#Override
TextView textt;
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_fragment1, container, false);
textt = (TextView)view.findViewById(R.id.textview);
return view;
}
public void updateText() {
textt.setText("some text");
}
}
and:
public class Fragment1 extends Fragment {
//#Nullable
//#Override
View view;
public View onCreateView(LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
view = inflater.inflate(R.layout.fragment_fragment1, container, false);
return view;
}
public void updateText() {
((TextView)view.findViewById(R.id.textview)).setText("some text");
}
}
MainActivity:
public class MainActivity extends AppCompatActivity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
FragmentTransaction ft = getSupportFragmentManager().beginTransaction();
Fragment1 frg1 = new Fragment1();
ft.replace(R.id.fragment_container, frg1);
ft.addToBackStack(null);
ft.commit();
frg1.updateText();
}
}
why these codes providing different outcome?
my project
frg1.updateText(); is called before the onCreateView lifecycle method of your fragment is called.. You should call the method after you set
textt = (TextView)view.findViewById(R.id.textview);
View view = inflater.inflate(R.layout.fragment_fragment1, container, false);
textt = (TextView)view.findViewById(R.id.textview);
this.updateText();//here
return view;
Check out fragment lifecycle docs regarding onCreateView
The system calls this when it's time for the fragment to draw its user interface for the first time.
This will happen when fragment is loaded not when it is created in your activity.
Here, the textview is not created when you call the updateText function.
Do such calls inside your fragment. Not on the activity which houses the fragment.
i have a fragment inside a activity, this fragment contains a viewpager, this is the code:
public class RepliesContainerFragment extends Fragment {
#InjectView(R.id.viewPager)
ViewPager pager;
private PagerAdapter adapter;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
ReplyActivity replyActivity = (ReplyActivity) getActivity();
List<Replie> replies = getArguments().getParcelableArrayList("replies");
adapter = new PagerAdapter(replyActivity.getSupportFragmentManager(), replies);
setActionBar();
}
private void setActionBar() {
getActivity().getActionBar().setDisplayHomeAsUpEnabled(false);
getActivity().getActionBar().setIcon(getResources().getDrawable(R.drawable.ic_back));
getActivity().getActionBar().setDisplayHomeAsUpEnabled(true);
getActivity().getActionBar().setTitle("Respuestas");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.work_containter_replies, container, false);
ButterKnife.inject(this, view);
pager.setAdapter(adapter);
return view;
}
}
Inside the adapter i had instantiate some fragments like this:
public class ReplyFragment extends Fragment {
#InjectView(R.id.tvQuestion)
TextView tvQuestion;
#InjectView(R.id.frameContainter)
FrameLayout replyContainer;
private ReplyView replyView;
private String question;
private String currentReplie;
private int replieType;
private int questionId;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
replieType = getArguments().getInt("replyType");
question = getArguments().getString("question");
questionId = getArguments().getInt("questionId");
currentReplie = getArguments().getString("currentReplie");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
super.onCreateView(inflater, container, savedInstanceState);
View view = inflater.inflate(R.layout.work_reply_fragment, container, false);
ButterKnife.inject(this, view);
initQuestionText();
return view;
}
private void persistReply() {
ReplyActivity replyActivity = (ReplyActivity) getActivity();
if (replyActivity != null) {
//DO SOMETHING
//Notify to adapter from here
}
}
}
}
As you can see, i want to notify to my RepliesContainerFragment and his inside adapter that some event happens and do an action..
How can i do it this?
With broadcastreceivers, with callbacks(Interfaces)..?I am not sure.
The very simple solution for this is to pass a listener instance from your parent fragment to a child fragment. You have to create a listener interface, create an instance of it in your parent fragment, and pass that instance to all your children fragments.
By the way there is a topic regarding this problem in the official tutorial.
Hope this helps.
I think it is easier:
private void persistReply() {
ReplyActivity replyActivity = (ReplyActivity) getActivity();
if (replyActivity != null) {
//DO SOMETHING
RepliesContainerFragment frag = ((RepliesContainerFragment)this.getParentFragment());
frag.getAdapter().notifyDataSetChanged();
}
}
}
and make getter setter for adapter
I have seen Link1 for this issue but could understand it right. I have a fragment that loads a list. When i click the list item it opens another activity. But i press back button it loads the list again. I want it to be at the same scroll position where it was before. In above mentioned link it specifies to use flag but i haven't got the point.
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_dashboard);
android.app.Fragment fragment = new MeFragment();
getFragmentManager().beginTransaction().replace(R.id.layout_FragmentsContainer, fragment).addToBackStack(null).commit();
}
}
public class MeFragment extends Fragment
{
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
return inflater.inflate(R.layout.fragment_me, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
meLV = (ListView) getView().findViewById(R.id.lv_Inbox);
loadingListProgress = (ProgressBar) getView().findViewById(R.id.progress_LoadingList);
meList = new ArrayList<Message>();
meAdapter = new MessagesListAdapter(getActivity(), meList);
//addFooter();
meLV.setAdapter(meAdapter);
meLV.setOnItemClickListener(this);
pageCount = 0;
loadmoreProgressDialog = new ProgressDialog(getActivity());
loadmoreProgressDialog.setTitle("Please wait ...");
loadmoreProgressDialog.setMessage("Loading more ...");
loadmoreProgressDialog.setCancelable(true);
loadUserMessages();
meLV.setOnScrollListener(new EndlessScrollListener() {
#Override
public void onLoadMore(int page, int totalItemsCount) {
// TODO Auto-generated method stub
//addFooter();
loadmoreProgressDialog.show();
loadUserMessages();
}
});
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position,
long id) {
// TODO Auto-generated method stub
Utils.showToast_msg(getActivity(), "MessageItemClicked");
ReferralDetailFragment fragment = new ReferralDetailFragment();
getFragmentManager().beginTransaction().replace(R.id.layout_FragmentsContainer, fragment).addToBackStack(null).commit();
}
}
public class ReferralDetailFragment extends Fragment implements OnClickListener {
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_referraldetail,container, false);
linkToAcknowledge = (TextView) view.findViewById(R.id.lbl_Link_to_Acknowledge);
return view;
}
}
I implemented a simple solution for this in my app, basically when you press back to go to the fragment again, onCreateView() is called. Here in onCreateView() you have done all initialization, so we change
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
View view = inflater.inflate(R.layout.fragment_me, container, false);
/*
*Whatever you want to do
*
*/
return view;
}
to:
View view;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
if(view==null){
view = inflater.inflate(R.layout.fragment_me, container, false);
/*
*Whatever you want to do
*
*/
}
else{
((ViewGroup)view.getParent()).removeView(view);
}
return view;
}
Here, we move View view outside and make it a class variable. So if it is the first time the fragment is called, it is null and the initialization occurs, otherwise it goes to else black. Else block is required because onCreateView() adds whatever it returns as a child of the view's parent, so since view is already there, we remove it and onCreateView automatically adds it again.
According to our exchange in the comments, I completely deletde my answer and re-write a new one.
I copy/paste the code from one of my apps and removing the useless things and changing the names. Hope there is not too many typing mistakes, at that it is the minimum required to have it working.
When I pop back to FirstFragment from SecondFragment, the scroll position of FirstFragment is the same as when I clicked an item to load the SecondFragment.
Note that I don't extend FragmentActivity. I have an activity which loads the fragments.
Extend/modify to match your needs.
MainActivity :
public class MainActivity extends Activity {
#Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_layout);
}
}
FirstFragment Class :
public class FirstFragment extends Fragment implements OnItemClickListener {
private ListView mListView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.first_fragment_layout, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
mListView = (ListView) getView().findViewById(R.id.listview_first_fragment);
mListView.setAdapter(mAdapter); // depends on your adapter
mListView.setOnItemClickListener(this);
}
#Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
mListView.setItemChecked(position, true);
//in case you need, set the bundle here, for example pass the position
Bundle arguments = new Bundle();
arguments.putInt("position", position);
SecondFragment secondFragment = new SecondFragment();
secondFragment.setArguments(arguments);
getFragmentManager().beginTransaction().replace(R.id.fragment_container, secondFragment).addToBackStack(null).commit();
}
}
SecondFragment Class :
public class SecondFragment extends Fragment {
private Integer mPosition;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.second_fragment_layout, container, false);
}
#Override
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
Bundle arguments = getArguments();
if (arguments == null) {
mPosition= 0;
} else {
mPosition= arguments.getInt("Position");
}
}
}
What you are trying to achieve may be done with help of savedInstanceState. i also had this kind of problem which i resolved by using add() method instead of replace() in transition.
If you can change your method or already not using add() than give it a shot.
and if add() method didn't do the trick then check the implementation of savedInstanceState.
correctly save instance state.
How to save states of fragment views.
Hi I am trying to get an id of some View in a Fragment from a string, however it doesn't seem to work... Is there a special case for fragments?
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View singleplayerView = inflater.inflate(R.layout.singleplayer_tab, container, false);
setupMap();
return singleplayerView;
}
private void setupRank() {
TextView view = (TextView) getByStringId("rank0");
view.setText("hello");
}
private final View getByStringId(final String id) {
return findViewById(getResources().getIdentifier(id, "id", getActivi
ty().getPackageName()));
}
So I am trying to set the textView field rank0 in the layout that is used for my fragment... but right now it gets a NUllPointer because it couldnt find the id
Thank you
you can define your Layout In your onCreateView() inside Fragments like this:
View V = new View(getActivity());
V = inflater.inflate(R.layout.fragment_layout,container, false);
Then
TextView SomeField = (TextView)V.findViewById(R.id.TxtSomeField);
Inside fragment, add getActivity before findViewById:
getActivity().findViewById(...);
Try this,
String id;
#Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
Bundle extra = getArguments();
id = extra.getString("id", "");
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_calendar_details, container, false);
Button b = (Button) view.findViewById(id);
return view;
}
I am trying to implement Fragments in my Project using the https://github.com/JakeWharton/Android-ViewPagerIndicator plugin.
My Fragment
public final class NearByFragment extends Fragment {
private static String TAG = "bMobile";
public static NearByFragment newInstance(String content) {
NearByFragment fragment = new NearByFragment();
return fragment;
}
#Override
public void onCreate(Bundle savedInstanceState) {
Log.d(TAG, "onCreate");
super.onCreate(savedInstanceState);
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.d(TAG, "onCreateView");
return inflater.inflate(R.layout.fragment_search_nearby, null);
}
}
Now I want to execute some code like start start a new thread and download a JSON from the server and then assign a list view from the content I download. In fragments we are assigning views in onCreateView. so where should I write the
listview = (ListView) findViewById(R.id.list_items);
((TextView) findViewById(R.id.title_text))
.setText(R.string.description_blocked);
and other code to generate the Fragment view ?
You can search within the view that you just inflated:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
Log.d(TAG, "onCreateView");
View v = inflater.inflate(R.layout.fragment_search_nearby, null);
listview = (ListView)v.findViewById(R.id.list_items);
((TextView)v.findViewById(R.id.title_text))
.setText(R.string.description_blocked);
return v;
}
You can also use the Fragment.getView() function elsewhere in your code and call that view's findViewById() member.
You can use getActivity().findByView() from the Fragment if you want to have access to the layout elements. Alternatively, you can just put the findByView() call in the main Activity.