Настройка текстового поля фрагмента

Question

У меня есть два вида деятельности School.java и SchoolDetails.java.Under SchoolDetails. Я использовал фрагменты, реализуя swipeable tabs.I передал значение из Schools.java в SchoolDetails.java с использованием намерения. Теперь я хотите установить это значение, полученное из Schools.java, в textField, который находится внутри фрагмента активности SchoolDetails.java.I получил следующую ошибку.

java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.content.Intent.getStringExtra(java.lang.String)' on a null object reference 

Это все, что я сделал в Schools.java я передал название школы SchoolDetails

School.java

import android.app.ProgressDialog; 
import android.content.Intent; 
import android.support.v7.app.ActionBar; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.util.Log; 
import android.view.Menu; 
import android.view.MenuInflater; 
import android.view.MenuItem; 
import android.view.View; 
import android.widget.AdapterView; 
import android.widget.ListView; 

import com.android.volley.Response; 
import com.android.volley.VolleyError; 
import com.android.volley.VolleyLog; 
import com.android.volley.toolbox.JsonArrayRequest; 
import com.example.user.educationhunt.adapter.CustomListAdapter; 
import com.example.user.educationhunt.fragment.About; 
import com.example.user.educationhunt.pojos.AppController; 
import com.example.user.educationhunt.pojos.OurSchool; 

import org.json.JSONArray; 
import org.json.JSONException; 
import org.json.JSONObject; 

import java.io.Serializable; 
import java.util.ArrayList; 
import java.util.List; 

public class School extends AppCompatActivity{ 

    // Log tag 
    private static final String TAG = School.class.getSimpleName(); 

    // Billionaires json url 
    private static final String url = "http://myeducationhunt.com/public/schools"; 

    private ProgressDialog pDialog; 
    private List<OurSchool> ourSchoolsListItems = new ArrayList<OurSchool>(); 
    private ListView listView; 
    private CustomListAdapter adapter; 

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

     ActionBar actionBar=getSupportActionBar(); 
     actionBar.setDisplayHomeAsUpEnabled(true); 
     actionBar.setTitle("Schools"); 


     listView = (ListView) findViewById(R.id.list); 
     adapter = new CustomListAdapter(this, ourSchoolsListItems); 
     listView.setAdapter(adapter); 

     listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
      @Override 
      public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 

       OurSchool ourSchool=new OurSchool(); 
       Intent i=new Intent(School.this,SchoolDetails.class); 

       i.putExtra("id", ourSchoolsListItems.get(position).schoolId); 
       i.putExtra("name", ourSchoolsListItems.get(position).schoolName); 
       i.putExtra("location", ourSchoolsListItems.get(position).schoolLocation); 
       i.putExtra("logo", ourSchoolsListItems.get(position).schoolLogo); 
       i.putExtra("email", ourSchoolsListItems.get(position).schoolEmail); 
       i.putExtra("website", ourSchoolsListItems.get(position).schoolEmail); 
       i.putExtra("created_at", ourSchoolsListItems.get(position).createdAt); 
       i.putExtra("updated_at", ourSchoolsListItems.get(position).updatedAt); 

       startActivity(i); 

      } 
     }); 

     pDialog = new ProgressDialog(this); 
// Showing progress dialog before making http request 
     pDialog.setMessage("Loading…"); 
     pDialog.show(); 

// Creating volley request obj 
     JsonArrayRequest billionaireReq = new JsonArrayRequest(url, 
       new Response.Listener<JSONArray>() { 
        @Override 
        public void onResponse(JSONArray response) { 
         Log.d(TAG, response.toString()); 
         hidePDialog(); 

         // Parsing json 
         for (int i = 0; i < response.length(); i++) { 
          try { 

           JSONObject obj = response.getJSONObject(i); 
           OurSchool ourSchool = new OurSchool(); 

           ourSchool.schoolId=obj.getInt("id"); 
           ourSchool.schoolName=obj.getString("name"); 
           ourSchool.schoolLocation=obj.getString("location"); 
           ourSchool.schoolLogo=obj.getString("logo"); 
           ourSchool.schoolEmail=obj.getString("email"); 
           ourSchool.schoolWebsite=obj.getString("website"); 
           ourSchool.createdAt=obj.getString("created_at"); 
           ourSchool.updatedAt=obj.getString("updated_at"); 

          // adding schools to ourSchool list 
           ourSchoolsListItems.add(ourSchool); 

          } catch (JSONException e) { 
           e.printStackTrace(); 
          } 
         } 

         adapter.notifyDataSetChanged(); 
        } 
       }, new Response.ErrorListener() { 
      @Override 
      public void onErrorResponse(VolleyError error) { 
       VolleyLog.d(TAG, "Error: " + error.getMessage()); 
       hidePDialog(); 
      } 
     }); 

    // Adding request to request queue 
     AppController.getInstance().addToRequestQueue(billionaireReq); 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     hidePDialog(); 
    } 

    private void hidePDialog() { 
     if (pDialog != null) { 
      pDialog.dismiss(); 
      pDialog = null; 
     } 

    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
      case android.R.id.home: 
       onBackPressed(); 
       return true; 
      case R.id.schoolSearch: 
      default: 
       return super.onOptionsItemSelected(item); 
     } 
    } 

    @Override 
    public boolean onCreateOptionsMenu(Menu menu) { 
     MenuInflater inflater = getMenuInflater(); 
     inflater.inflate(R.menu.search, menu); 
     return true; 
    } 
} 

SchoolDetails.java

package com.example.user.educationhunt; 

import android.content.Intent; 
import android.support.design.widget.TabLayout; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentPagerAdapter; 
import android.support.v4.app.FragmentTransaction; 
import android.support.v4.view.ViewPager; 
import android.support.v7.app.AppCompatActivity; 
import android.os.Bundle; 
import android.support.v7.widget.Toolbar; 

import com.example.user.educationhunt.fragment.About; 
import com.example.user.educationhunt.fragment.Admission; 
import com.example.user.educationhunt.fragment.FeeStructure; 
import com.example.user.educationhunt.fragment.Majors; 
import com.example.user.educationhunt.pojos.OurSchool; 

import org.junit.runner.Describable; 

import java.util.ArrayList; 
import java.util.List; 

public class SchoolDetails extends AppCompatActivity{ 

    private Toolbar toolbar; 
    private TabLayout tabLayout; 
    private ViewPager viewPager; 

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

     toolbar = (Toolbar) findViewById(R.id.toolbar); 
     setSupportActionBar(toolbar); 

     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 

     viewPager = (ViewPager) findViewById(R.id.viewpager); 
     setupViewPager(viewPager); 

     tabLayout = (TabLayout) findViewById(R.id.tabs); 
     tabLayout.setupWithViewPager(viewPager); 

     About aboutFragment= (About) getSupportFragmentManager().findFragmentById(R.id.aboutFragment); 
     aboutFragment.aboutSchoolName.setText("name:"+ getIntent().getStringExtra("name")); 

    } 

    private void setupViewPager(ViewPager viewPager) { 
     ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager()); 
     adapter.addFragment(new About(), "ABOUT US"); 
     adapter.addFragment(new Admission(), "ADMISSION"); 
//  adapter.addFragment(new Majors(), "MAJORS"); 
     adapter.addFragment(new FeeStructure(), "FEE"); 
     viewPager.setAdapter(adapter); 
    } 

    class ViewPagerAdapter extends FragmentPagerAdapter { 
     private final List<Fragment> mFragmentList = new ArrayList<>(); 
     private final List<String> mFragmentTitleList = new ArrayList<>(); 

     public ViewPagerAdapter(FragmentManager manager) { 
      super(manager); 
     } 

     @Override 
     public Fragment getItem(int position) { 
      return mFragmentList.get(position); 
     } 

     @Override 
     public int getCount() { 
      return mFragmentList.size(); 
     } 

     public void addFragment(Fragment fragment, String title) { 
      mFragmentList.add(fragment); 
      mFragmentTitleList.add(title); 
     } 

     @Override 
     public CharSequence getPageTitle(int position) { 
      return mFragmentTitleList.get(position); 
     } 
    } 
} 

И наконец, это мой о фрагменте

package com.example.user.educationhunt.fragment; 


import android.os.Bundle; 
import android.support.v4.app.Fragment; 
import android.support.v4.app.FragmentManager; 
import android.support.v4.app.FragmentTransaction; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.TextView; 

import com.example.user.educationhunt.R; 
import com.example.user.educationhunt.School; 
import com.example.user.educationhunt.SchoolDetails; 
import com.example.user.educationhunt.pojos.OurSchool; 
import com.google.android.gms.maps.CameraUpdate; 
import com.google.android.gms.maps.CameraUpdateFactory; 
import com.google.android.gms.maps.GoogleMap; 
import com.google.android.gms.maps.MapView; 
import com.google.android.gms.maps.MapsInitializer; 
import com.google.android.gms.maps.OnMapReadyCallback; 
import com.google.android.gms.maps.model.LatLng; 
import com.google.android.gms.maps.model.MarkerOptions; 

import org.junit.runner.Describable; 

import java.io.Serializable; 

/** 
* A simple {@link Fragment} subclass. 
*/ 
public class About extends Fragment implements OnMapReadyCallback{ 

    MapView mapView; 
    GoogleMap map; 
    public TextView aboutSchoolName,aboutSchoolLocation,aboutSchoolNumber,aboutSchoolEmail,aboutSchoolWebsite,aboutSchoolCategory; 


    @Override 
    public View onCreateView(LayoutInflater inflater, ViewGroup container, 
          Bundle savedInstanceState) { 
     // Inflate the layout for this fragment 
     View v = inflater.inflate(R.layout.fragment_about, container, false); 

     aboutSchoolName= (TextView) v.findViewById(R.id.about_school_name); 
     aboutSchoolLocation= (TextView) v.findViewById(R.id.about_school_location); 
     aboutSchoolNumber= (TextView) v.findViewById(R.id.about_school_number); 
     aboutSchoolCategory= (TextView) v.findViewById(R.id.about_school_category); 
     aboutSchoolEmail= (TextView) v.findViewById(R.id.about_school_email); 
     aboutSchoolWebsite= (TextView) v.findViewById(R.id.about_school_website); 

//  School school=new School(); 
//  aboutSchoolName.setText("name:"+ school.getIntent().getStringExtra("name")); 



     // Gets the MapView from the XML layout and creates it 
     mapView = (MapView) v.findViewById(R.id.mapview); 
     mapView.onCreate(savedInstanceState); 

     // Gets to GoogleMap from the MapView and does initialization stuff 
     map = mapView.getMap(); 
     map.getUiSettings().setMyLocationButtonEnabled(false); 
     map.setMyLocationEnabled(true); 

     // Needs to call MapsInitializer before doing any CameraUpdateFactory calls 
     MapsInitializer.initialize(this.getActivity()); 

     // Updates the location and zoom of the MapView 
     CameraUpdate cameraUpdate = CameraUpdateFactory.newLatLngZoom(new LatLng(27.6933, 85.3211), 15); 
     map.animateCamera(cameraUpdate); 
     onMapReady(map); 

     return v; 
    } 

    @Override 
    public void onResume() { 
     mapView.onResume(); 
     super.onResume(); 
    } 

    @Override 
    public void onDestroy() { 
     super.onDestroy(); 
     mapView.onDestroy(); 
    } 

    @Override 
    public void onLowMemory() { 
     super.onLowMemory(); 
     mapView.onLowMemory(); 
    } 

    @Override 
    public void onMapReady(GoogleMap map) { 
     map.addMarker(new MarkerOptions() 
       .position(new LatLng(27.6933, 85.3211)) 
       .title("St. Xavier's College")); 
    } 
} 

Может кто-нибудь, пожалуйста, помогите мне?

Answer 1

Попытайтесь получить дополнительные функции от Намерения в Деятельности и затем передать любые дополнительные данные фрагментам, создав их с помощью аргументов. Следуйте за этим, Where/How to getIntent().getExtras() in an Android Fragment?

Answer 2

От деятельности к фрагментировать

About about = new About(); 
    Bundle args = new Bundle(); 
    args.putString("key", value); 
    about.setArguments(args); 

В Фрагмент

Bundle args = getArguments(); 
String value = args.getInt("key");