How to show my spinner within one fragment - java

I am on creating an application and at the moment, I have created two fragments which is going to be a "navigation" sort of thing. On the second of the two fragments, I have put a spinner on which is where the user would be able to select a particular option. All of the spinners have unique ID's but the findViewById method cannot be resolved
All of the strings are in the strings xml file and when I tried this spinner in my testing app, it worked
public class Frag2 extends Fragment implements AdapterView.OnItemSelectedListener{
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.frag2_layout, container, false);
Spinner spinner = findViewById (R.id.spinner1);
ArrayAdapter.createFromResource(getActivity(), R.array.insulin, android.R.layout.simple_spinner_item);
ArrayAdapter<CharSequence> adapter;
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
spinner.setAdapter(adapter);
spinner.setOnItemSelectedListener(this);
}
#Override
public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
String text = parent.getItemAtPosition(position).toString();
Toast.makeText(parent.getContext(), text, Toast.LENGTH_SHORT).show();
}
#Override
public void onNothingSelected(AdapterView<?> parent) {
}
}
The spinner should work within the one fragment and then I would like to have it another few times


This is fragment you're dealing with, not an activity. Fragment doesn't extend Context or View classes and does not have this findViewById method.
What you should do is to move your code from onCreateView to onViewCreated which gets a reference to the root view as a parameter. Then use the same method but with that view, as below:
#Override
public void onViewCreated(#NonNull View view, #Nullable Bundle savedInstanceState) {
Spinner spinner = view.findViewById(R.id.spinner1);
...
}
Another thing you may do is replacing:
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
return inflater.inflate(R.layout.frag2_layout, container, false);
Spinner spinner = findViewById (R.id.spinner1);
// I'm not sure how you didn't see all errors when writing code after a return statement.
...
}
With:
#Nullable
#Override
public View onCreateView(#NonNull LayoutInflater inflater, #Nullable ViewGroup container, #Nullable Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.frag2_layout, container, false);
Spinner spinner = view.findViewById(R.id.spinner1);
...
return view; // after finishing all logic.
}
UPDATE:
Didn't see that there is also a problem with the ArrayAdapter.
As mentioned in Csongi77 answer, you need to to instantiate the adapter properly. Again, the fragment cannot use as context, you must use the containing activity for that:
ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(), R.array.insulin, android.R.layout.simple_spinner_item);
ArrayAdapter.createFromResource creates and returns a new adapter and currently you just disposing it immediately by not saving its reference.


I think first you should instantiate adapter like this: ArrayAdapter<CharSequence> adapter = ArrayAdapter.createFromResource(getActivity(), R.array.insulin, android.R.layout.simple_spinner_item); please let me know if it works. Regards, Csongi

Related

Pass data between fragments with Bundle

I read a lot of discussion about that, and someone suggests to use Bundle to pass data between two fragments in the same activity...I tried some come, but it didn't worked.
I have 2 fragments in my GroupDetailActivity. The paymentFragment, which download data from a database and show them in a listView, and the fragment FragmentReport, which displays a report of the payments.
So, after the paymentFragment get the data, I need to pass some of them to the second fragment. That's my code:
PaymentFragment:
final Bundle bundle = new Bundle();
final FragmentReport fragment = new FragmentReport();
// This is inside the onCreateView, where I get the the data from the db and show them in a listview
bundle.putInt("num_of_pay", cont);
Log.v("cont", String.valueOf(cont)); // it display the correct number of person
fragment.setArguments(bundle);
getFragmentManager().beginTransaction().replace(R.id.container, fragment);
Then, in my FragmentReport, inside the OnCreateView:
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View rootView=inflater.inflate(R.layout.report_fragment,container,false);
numberOfPaymentTV = rootView.findViewById(R.id.n_payment_tv);
Bundle args = this.getArguments();
if (args != null){
numberOfPaymentTV.setText(args.getInt("num_of_pay"));
Log.v("totalPayment", String.valueOf(args.getInt("num_of_pay"))); // I don't get any log, maybe this fragment doesn't receive the data
}
return rootView;
}
}
I don't get any error, but the textView doesn't show the "cont" value.
Maybe I could use sharedPreferences? Is it possibile achieve that with Bundle?

You can get args in onCreate() function.
private Bundle bundle;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_blank, container, false);
((TextView) view.findViewById(R.id.textView))
.setText(String.valueOf(bundle.getInt("KEY")));
return view;
}
#Override
public void onCreate(#Nullable Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.bundle = getArguments();
}

You should use the String.valueOf(int) when setting an int as text in a TextView:
numberOfPaymentTV.setText(String.valueOf(getArguments().getInt("num_of_pay"))

.getView.findViewById in fragment returning NullPointerException [duplicate]

I am trying to create an ImageView in a Fragment which will refer to the ImageView element which I have created in the XML for the Fragment. However, the findViewById method only works if I extend an Activity class. Is there anyway of which I can use it in Fragment as well?
public class TestClass extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
ImageView imageView = (ImageView)findViewById(R.id.my_image);
return inflater.inflate(R.layout.testclassfragment, container, false);
}
}
The findViewById method has an error on it which states that the method is undefined.

Use getView() or the View parameter from implementing the onViewCreated method. It returns the root view for the fragment (the one returned by onCreateView() method). With this you can call findViewById().
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
ImageView imageView = (ImageView) getView().findViewById(R.id.foo);
// or (ImageView) view.findViewById(R.id.foo);
As getView() works only after onCreateView(), you can't use it inside onCreate() or onCreateView() methods of the fragment .

You need to inflate the Fragment's view and call findViewById() on the View it returns.
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView) view.findViewById(R.id.my_image);
return view;
}

Inside Fragment class you will get onViewCreated() override method where you should always initialize your views as in this method you get view object using which you can find your views like :
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
view.findViewById(R.id.yourId).setOnClickListener(this);
// or
getActivity().findViewById(R.id.yourId).setOnClickListener(this);
}
Always remember in case of Fragment that onViewCreated() method will not called automatically if you are returning null or super.onCreateView() from onCreateView() method.
It will be called by default in case of ListFragment as ListFragment return FrameLayout by default.
Note: you can get the fragment view anywhere in the class by using getView() once onCreateView() has been executed successfully.
i.e.
getView().findViewById("your view id");

I realise this is an old question, but the prevailing answer leaves something to be desired.
The question is not clear what is required of imageView - are we passing it back as the view, or merely saving a reference for later?
Either way, if the ImageView is coming from the inflated layout, the correct way to do this would be:
public class TestClass extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView)v.findViewById(R.id.my_image);
return v;
}
}

Get first the fragment view and then get from this view your ImageView.
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView) view.findViewById(R.id.my_image);
return view;
}

Inside Fragment class we get onViewCreated() override method where we should always initialize our views because in this method we get view object. Using this object we can find our views like below:
class MyFragment extends Fragment {
private ImageView imageView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.my_fragment_layout, container, false);
}
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
//initialize your view here for use view.findViewById("your view id")
imageView = (ImageView) view.findViewById(R.id.my_image);
}
}

You could also do it in the onActivityCreated Method.
public void onActivityCreated(Bundle savedInstanceState) {
super.onActivityCreated(savedInstanceState);
}
Like they do here: http://developer.android.com/reference/android/app/Fragment.html (deprecated in API level 28)
getView().findViewById(R.id.foo);
and
getActivity().findViewById(R.id.foo);
are possible.

getView() will give the root view
View v = getView().findViewByID(R.id.x);

You can override onViewCreated() which is called right after all views had been inflated. It's the right place to fill in your Fragment's member View variables. Here's an example:
class GalleryFragment extends Fragment {
private Gallery gallery;
(...)
#Override
public void onViewCreated(View view, Bundle savedInstanceState) {
gallery = (Gallery) view.findViewById(R.id.gallery);
gallery.setAdapter(adapter);
super.onViewCreated(view, savedInstanceState);
}
}

The method getView() wont work on fragments outside OnCreate and similar methods.
You have two ways, pass the view to the function on the oncreate (what means you can only run your functions when the view is being created) or set the view as a variable:
private View rootView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.fragment_contatos, container, false);
}
public void doSomething () {
ImageView thumbnail = (ImageView) rootView.findViewById(R.id.someId);
}

1) first inflate layout of Fragment then you can use findviewbyId .
View view = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView) view.findViewById(R.id.my_image);
return view;

EditText name = (EditText) getView().findViewById(R.id.editText1);
EditText add = (EditText) getView().findViewById(R.id.editText2);

agreed with calling findViewById() on the View.
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View V = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView) V.findViewById(R.id.my_image);
return V;
}

Note :
From API Level 26, you also don't need to specifically cast the result of findViewById as it uses inference for its return type.
So now you can simply do,
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = view.findViewById(R.id.my_image); //without casting the return type
return view;
}

Use
imagebutton = (ImageButton) getActivity().findViewById(R.id.imagebutton1);
imageview = (ImageView) getActivity().findViewById(R.id.imageview1);
it will work

According to the documentation on API level 11
Reference, in Back Stack
http://developer.android.com/reference/android/app/Fragment.html
short code
/**
* The Fragment's UI is just a simple text view showing its
* instance number.
*/
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.hello_world, container, false);
View tv = v.findViewById(R.id.text);
((TextView)tv).setText("Fragment #" + mNum);
tv.setBackgroundDrawable(getResources().getDrawable(android.R.drawable.gallery_thumb));
return v;
}

Using getView() returns the view of the fragment, then you can call findViewById() to access any view element in the fragment view.

Try this it works for me
public class TestClass extends Fragment {
private ImageView imageView;
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.testclassfragment, container, false);
findViews(view);
return view;
}
private void findViews(View view) {
imageView = (ImageView) view.findViewById(R.id.my_image);
}
}

1) Declare your layout file.
public View onCreateView(LayoutInflater inflater,ViewGroup container,
Bundle savedInstanceState) {
return inflate(R.layout.myfragment, container, false);
}
2)Then, get the id of your view
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
TextView nameView = (TextView) view.findViewById(R.id.textview1);
}

The best way to implement this is as follows:
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
rootView = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView) rootView.findViewById(R.id.my_image);
return rootView
}
In this way, the rootView can be used for each control defined in the xml layout and the code is much cleaner in this way.
Hope this helps :)

Try This:
View v = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView img = (ImageView) v.findViewById(R.id.my_image);
return v;

try
private View myFragmentView;
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
{
myFragmentView = inflater.inflate(R.layout.myLayoutId, container, false);
myView = myFragmentView.findViewById(R.id.myIdTag)
return myFragmentView;
}

Use gradle skeleton plugin, it will automatically generate the view holder classes with the reference to your layout.
public class TestClass extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
MyLayout myLayout = new MyLayout(inflater, container, false);
myLayout.myImage.setImageResource(R.drawable.myImage);
return myLayout.view;
}
}
Now assuming you had an ImageView declared in your my_layout.xml file, it will automatically generate myLayout class for you.

I like everything to be structured. You can do in this way.
First initialize view
private ImageView imageView;
Then override OnViewCreated
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
findViews(view);
}
Then add a void method to find views
private void findViews(View v) {
imageView = v.findViewById(R.id.img);
}

//here you can do it by
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState)
{
// Inflate the layout for this fragment
final View view = inflater.inflate(R.layout.fragment_apple, container,
false);
ist = view.findViewById(R.id.linearLink);
second = view.findViewById(R.id.linearPhone);
return view;

ImageView imageView;
public View onCreateView(LayoutInflater inflater,
ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.testclassfragment, container, false);
imageView = view.findViewById(R.id.my_image);
return view;
}

You can call findViewById() with the Activity Object you get inside your public void onAttach(Activity activity) method inside your Fragment.
Save the Activity into a variable for example:
In the Fragment class:
private Activity mainActivity;
In the onAttach() method:
this.mainActivity=activity;
Finally execute every findViewById through the vairable:
mainActivity.findViewById(R.id.TextView);

Inside onCreateView method
1) first you have to inflate the layout/view you want to add
eg. LinearLayout
LinearLayout ll = inflater.inflate(R.layout.testclassfragment, container, false);
2) Then you can find your imageView id from layout
ImageView imageView = (ImageView)ll.findViewById(R.id.my_image);
3)return the inflated layout
return ll;

You have to inflate the view
public class TestClass extends Fragment {
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View v = inflater.inflate(R.layout.testclassfragment, container, false);
ImageView imageView = (ImageView)v.findViewById(R.id.my_image);
return v
}}

There is one more method called onViewCreated.
#Override
public void onViewCreated(View view, #Nullable Bundle savedInstanceState) {
super.onViewCreated(view, savedInstanceState);
ImageView imageView = (ImageView) view.findViewById(R.id.imageview1);
}

Unfortunately, app has stopped,how can I make this work onCreateView?

Previously, I had a similar issue, app crashes when trying to access (or findByID), it turned out, I've put the textview in the wrong method, Now I have only one method, and I am working with a fragment, the method onCreateView and my app keeps crashing:
public class InfoFragment extends Fragment {
public InfoFragment() {
// Required empty public constructor
}
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
TextView n = (TextView) getView().findViewById(R.id.nama);
n.setText("Some String");
// Inflate the layout for this fragment
return inflater.inflate(R.layout.fragment_info, container, false);
}
}
Originally, I had the line looking like this :
TextView n = (TextView) findViewById(R.id.nama);
However,the compiler gave me an error saying it can't find the method findViewById, so some research showed that I should add getView() , I did, and the error disappeared, but now the app is crashing, any ideas?

#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View view = inflater.inflate(R.layout.fragment_info, container, false);
TextView n = (TextView) view.findViewById(R.id.nama);
n.setText("Some String");
return view;
}
You don't have a view yet in that part of code. Inflate it first and use after.

Inflate your layout first, then you can use it to find the TextView:
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootView = inflater.inflate(R.layout.fragment_info, container, false);
TextView n = (TextView) rootView.findViewById(R.id.nama);
n.setText("Some String");
return rootView;
}

Adding calculator to navigation drawer

I've got a problem. For school project I have to create app in Android Studio with few activities so i decided to add Navigation Drawer, but when i try to create simple calculator to app i can't even reference button or textview. This is code for activity where I want to create calculator. Also I have to add Map Activity and SQLite Database.
public class Calculator_main extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.calculator, container, false);
return rootview;
}
}

Use rootView to find your item when referencing in a Fragment:
public class Calculator_main extends Fragment {
#Nullable
#Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
View rootview = inflater.inflate(R.layout.calculator, container, false);
//Notice the TextView being referenced with rootView in front of the findViewById statement
TextView namefield = (TextView) rootView.findViewById(R.id.namefield);
return rootview;
}
}
You need to do this when using Fragment, as this is the only way your app can reference an item in your Fragment's XML view
This is however not necessary in an Activity and should not be confused with the method of referencing in a Fragment

Android, Java: Bundles & Views for Fragments

I have a fragment, that i want to put a textview which will have a 3 strings stored in it from the 'Main Activity'
The strings that I need to pass will come from the Main Activity and will be passed into FragmentClass
The issue is that its not recognising findViewById, i understand this is something to do with the views? Could someone advise me on how i could get this editText working and then how i can pass a bundle of strings from the MainActivity to the FragmentClass.
#SuppressLint("NewApi")
public class FragmentClass extends Fragment {
#Override
public View onCreateView(LayoutInflater inflater,
ViewGroup container, Bundle savedInstanceState) {
//Inflate the layout for this fragment
return inflater.inflate(
R.layout.new_fragment, container, false);
// View rootView = inflater.inflate(R.layout.get_data, container, false);
TextView FragmentTextView = (TextView)findViewById(R.id.FragmentTextView);
}
}

Change to
#Override
public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) {
View view =inflater.inflate(R.layout.new_fragment, container, false);
TextView FragmentTextView = (TextView)view.findViewById(R.id.FragmentTextView);
return view;
}
Also you have #SuppressLint("NewApi") you have suppressed lint warning. Probably indicates that some features are available in new api's only. Do check your min sdk version in manifest

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