Activity send data to Fragment with interface

Question

I want to activity send fragment. I have a error you see below photo. Activity to fragment data send. i want to do when listView onClick my fragment that il value temp data. Fragment want to see humidity value ,temp value when setOnItemClickListener

MainActivity.java

public class MainActivity extends AppCompatActivity {
private String text ;
private TextView textView, textView2,textView3,textView4;
private SearchView searchView;
private ListView listView ;
private String[] il={"Adana", "Adıyaman", "Afyon", "Ağrı", "Amasya", "Ankara", "Antalya", "Artvin",
        "Aydın", "Balıkesir", "Bilecik", "Bingöl", "Bitlis", "Bolu", "Burdur", "Bursa", "Çanakkale",
        "Çankırı", "Çorum", "Denizli", "Diyarbakır", "Edirne", "Elazığ", "Erzincan", "Erzurum", "Eskişehir",
        "Gaziantep", "Giresun", "Gümüşhane", "Hakkari", "Hatay", "Isparta", "Mersin", "İstanbul", "İzmir",
        "Kars", "Kastamonu", "Kayseri", "Kırklareli", "Kırşehir", "Kocaeli", "Konya", "Kütahya", "Malatya",
        "Manisa", "Kahramanmaraş", "Mardin", "Muğla", "Muş", "Nevşehir", "Niğde", "Ordu", "Rize", "Sakarya",
        "Samsun", "Siirt", "Sinop", "Sivas", "Tekirdağ", "Tokat", "Trabzon", "Tunceli", "Şanlıurfa", "Uşak",
        "Van", "Yozgat", "Zonguldak", "Aksaray", "Bayburt", "Karaman", "Kırıkkale", "Batman", "Şırnak",
        "Bartın", "Ardahan", "Iğdır", "Yalova", "Karabük", "Kilis", "Osmaniye", "Düzce"};
private ArrayAdapter<String> arrayAdapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    searchView= (SearchView) findViewById(R.id.searchView);
    listView= (ListView) findViewById(R.id.listView);

    final SendData sendData = (SendData) this;
    FragmentA fragmentA = new FragmentA() ;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.frameLayout,fragmentA,"fragA");
    transaction.commit();




    arrayAdapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,android.R.id.text1,il);
    listView.setAdapter(arrayAdapter);
    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            return false;
        }

        @Override
        public boolean onQueryTextChange(String newText) {
            arrayAdapter.getFilter().filter(newText);
            return false;
        }
    });


    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, final int position, long id) {
            text = (String) listView.getItemAtPosition(position);
            sendData.gonder(text);

        }
    });





}

}

FragmentA.java

public class FragmentA extends Fragment implements SendData {
private TextView textView, textView2,textView3,textView4;

View view ;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.fragment_a,container,false) ;

    textView4= (TextView) view. findViewById(R.id.textIsım);
    textView3= (TextView) view.findViewById(R.id.textView3);
    textView2= (TextView) view.findViewById(R.id.textView2);
    textView= (TextView) view. findViewById(R.id.textView);
    return view;
}

@Override
public void gonder(String isim) {
    Factory.getInstance().havaModel(isim,APPID_KEY).enqueue(new Callback<HavaModel>() {
        @Override
        public void onResponse(Call<HavaModel> call, Response<HavaModel> response) {
            textView.setText(Float.toString((float) (response.body().main.temp-273.15)));
            textView2.setText(Float.toString(response.body().coord.lon));
            textView3.setText(Integer.toString(response.body().main.humidity)+" %");
            textView4.setText(response.body().name);

        }

        @Override
        public void onFailure(Call<HavaModel> call, Throwable t) {

        }
    });
}

SendData.java

public interface SendData {
public void gonder(String isim) ;
 }

Thank you very much Your advice important for me I hope you will help me

Answer 1

You have to set your Interface by calling your activity.

Your MainActivity should be like this.

public class MainActivity extends AppCompatActivity {
private String text ;
private TextView textView, textView2,textView3,textView4;
private SearchView searchView;
private ListView listView ;
private SendData sendData; // initialize it globally

private String[] il={"Adana", "Adıyaman", "Afyon", "Ağrı", "Amasya", "Ankara", "Antalya", "Artvin",
        "Aydın", "Balıkesir", "Bilecik", "Bingöl", "Bitlis", "Bolu", "Burdur", "Bursa", "Çanakkale",
        "Çankırı", "Çorum", "Denizli", "Diyarbakır", "Edirne", "Elazığ", "Erzincan", "Erzurum", "Eskişehir",
        "Gaziantep", "Giresun", "Gümüşhane", "Hakkari", "Hatay", "Isparta", "Mersin", "İstanbul", "İzmir",
        "Kars", "Kastamonu", "Kayseri", "Kırklareli", "Kırşehir", "Kocaeli", "Konya", "Kütahya", "Malatya",
        "Manisa", "Kahramanmaraş", "Mardin", "Muğla", "Muş", "Nevşehir", "Niğde", "Ordu", "Rize", "Sakarya",
        "Samsun", "Siirt", "Sinop", "Sivas", "Tekirdağ", "Tokat", "Trabzon", "Tunceli", "Şanlıurfa", "Uşak",
        "Van", "Yozgat", "Zonguldak", "Aksaray", "Bayburt", "Karaman", "Kırıkkale", "Batman", "Şırnak",
        "Bartın", "Ardahan", "Iğdır", "Yalova", "Karabük", "Kilis", "Osmaniye", "Düzce"};
private ArrayAdapter<String> arrayAdapter;

public void setSendData(SendData sendData){     //create setter for interface
    this.sendData = sendData;
}

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);


    searchView= (SearchView) findViewById(R.id.searchView);
    listView= (ListView) findViewById(R.id.listView);
    FragmentA fragmentA = new FragmentA() ;
    FragmentManager fragmentManager = getFragmentManager();
    FragmentTransaction transaction = fragmentManager.beginTransaction();
    transaction.add(R.id.frameLayout,fragmentA,"fragA");
    transaction.commit();

    arrayAdapter=new ArrayAdapter<String>(this,android.R.layout.simple_list_item_1,android.R.id.text1,il);
    listView.setAdapter(arrayAdapter);
    searchView.setOnQueryTextListener(new SearchView.OnQueryTextListener() {
        @Override
        public boolean onQueryTextSubmit(String query) {
            return false;
        }

        @Override
        public boolean onQueryTextChange(String newText) {
            arrayAdapter.getFilter().filter(newText);
            return false;
        }
    });


    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, final int position, long id) {
            text = (String) listView.getItemAtPosition(position);
            sendData.gonder(text);

        }
    });
}

Your Fragment should be like this.

public class FragmentA extends Fragment implements SendData {
private TextView textView, textView2,textView3,textView4;

View view ;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, Bundle savedInstanceState) {
    view = inflater.inflate(R.layout.fragment_a,container,false) ;

    textView4= (TextView) view. findViewById(R.id.textIsım);
    textView3= (TextView) view.findViewById(R.id.textView3);
    textView2= (TextView) view.findViewById(R.id.textView2);
    textView= (TextView) view. findViewById(R.id.textView);
    if(getActivity() instanceOf MainActivity)
       (MainActivity)getActivity().setSendData(this);  //set your interface in MainActivity
    return view;
}

@Override
public void gonder(String isim) {
    Factory.getInstance().havaModel(isim,APPID_KEY).enqueue(new Callback<HavaModel>() {
        @Override
        public void onResponse(Call<HavaModel> call, Response<HavaModel> response) {
            textView.setText(Float.toString((float) (response.body().main.temp-273.15)));
            textView2.setText(Float.toString(response.body().coord.lon));
            textView3.setText(Integer.toString(response.body().main.humidity)+" %");
            textView4.setText(response.body().name);

        }

        @Override
        public void onFailure(Call<HavaModel> call, Throwable t) {

        }
    });
}

Hope it helps:)