フラグメンテーションする意図がありません

Question

フラグメンテーションの意図がありません。あるクラスから別のクラスにインテントを送信しようとしています。次に、そのフラグメントのsetArgumentを呼び出します。このフラグメントでは、switch文を使って、引数の値に基づいてリサイクラビューにデータを設定します。ここで

は、最初のアクティビティ（私は私が実際に多くのより多くがある、意図を設定する2つの位置示さました）です：

expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() { 
     @Override 
     public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { 
      if (groupPosition == 0) { 
       if (childPosition == 0) { 
        Intent intent = new Intent(getApplicationContext(), WorkoutDaysActivity.class); 
        intent.putExtra("workout", "w29w1"); 
        startActivity(intent); 
       } 
       if (childPosition == 1) { 
        Intent intent = new Intent(getApplicationContext(), WorkoutDaysActivity.class); 
        intent.putExtra("workout", "w29w1"); 
        startActivity(intent); 
       } 

断片が作成されます。ここ

あり、そしてI

public class WorkoutDaysActivity extends BaseActivity{ 

@Override 
protected void onCreate(@Nullable Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.workout_days); 
    mToolBar = activateToolbar(); 
    setUpNavigationDrawer(); 


    ViewPager vp = (ViewPager) findViewById(R.id.view_pager); 
    this.addPages(vp); 

    TabLayout tabLayout = (TabLayout) findViewById(R.id.tab_layout); 
//  tabLayout.setTabGravity(TabLayout.GRAVITY_FILL); 
    tabLayout.setupWithViewPager(vp); 
    tabLayout.setOnTabSelectedListener(listener(vp)); 

} 
private void addPages(ViewPager pager) { 
    MyFragPagerAdapter adapter = new MyFragPagerAdapter(getSupportFragmentManager()); 
    Intent intent = getIntent(); 
    String workout = intent.getStringExtra("workout"); 
    Bundle args = new Bundle(); 
    args.putString("workout", workout); 

    MondayFragment mondayFragment = new MondayFragment(); 
    mondayFragment.setArguments(args); 
    adapter.addPage(mondayFragment); 
    WedFragment wedFragment = new WedFragment(); 
    wedFragment.setArguments(args); 
    adapter.addPage(wedFragment); 
    FridayFragment fridayFragment = new FridayFragment(); 
    fridayFragment.setArguments(args); 
    adapter.addPage(fridayFragment); 

そして最後に、ここでは、私が値を設定するには、switchステートメントを使用しようと3つのフラグメントのクラスの1つです：

public class WedFragment extends Fragment { 

Bundle args = getArguments(); 
String workout3 = args.getString("workout"); 

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

//  //RECYCLERVIEW 
    RecyclerView rv = (RecyclerView) view.findViewById(R.id.mRecyclerWed); 
    rv.setLayoutManager(new LinearLayoutManager(this.getActivity())); 
    rv.setAdapter(new MyRecyclerAdapter(this.getActivity(), getWedWorkout())); 

    return view; 


} 

private ArrayList<Workout> getWedWorkout() { 
    //COLLECTION OF MONDAY WORKOUT 

    ArrayList<Workout> workout = new ArrayList<>(); 
    switch(workout3) { 
     case "w29w1" : { 
      Workout workouts = new Workout("Bench", "60", "6", "155", false); 

      //ADD TO COLLECTION 
      workout.add(workouts); 

      workouts = new Workout("Bench", "70", "5", "175", false); 
      workout.add(workouts); 

      break;} 
     case "w29w2" :{ 
      Workout workouts = new Workout("Squat", "60", "6", "155", false); 

      //ADD TO COLLECTION 
      workout.add(workouts); 

      workouts = new Workout("Squat", "70", "5", "175", false); 
      workout.add(workouts); 

     break;} 
    } return workout; 

引数を設定しようとする試み

そして、ここでアプリがクラッシュし、エラーがある：

WedFragment.java:24はこのラインである

08-03 13:53:11.917 32143-32143/com.bestworkouts.sheikoworkout E/AndroidRuntime: FATAL EXCEPTION: main 
                      Process: com.bestworkouts.sheikoworkout, PID: 32143 
                      java.lang.RuntimeException: Unable to start activity ComponentInfo{com.bestworkouts.sheikoworkout/com.bestworkouts.sheikoworkout.WorkoutDaysActivity}: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference 
                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3254) 
                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3350) 
                       at android.app.ActivityThread.access$1100(ActivityThread.java:222) 
                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1795) 
                       at android.os.Handler.dispatchMessage(Handler.java:102) 
                       at android.os.Looper.loop(Looper.java:158) 
                       at android.app.ActivityThread.main(ActivityThread.java:7229) 
                       at java.lang.reflect.Method.invoke(Native Method) 
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230) 
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120) 
                      Caused by: java.lang.NullPointerException: Attempt to invoke virtual method 'java.lang.String android.os.Bundle.getString(java.lang.String)' on a null object reference 
                       at com.bestworkouts.sheikoworkout.Fragments.WedFragment.<init>(WedFragment.java:24) 
                       at com.bestworkouts.sheikoworkout.WorkoutDaysActivity.addPages(WorkoutDaysActivity.java:47) 
                       at com.bestworkouts.sheikoworkout.WorkoutDaysActivity.onCreate(WorkoutDaysActivity.java:27) 
                       at android.app.Activity.performCreate(Activity.java:6876) 
                       at android.app.Instrumentation.callActivityOnCreate(Instrumentation.java:1135) 
                       at android.app.ActivityThread.performLaunchActivity(ActivityThread.java:3207) 
                       at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:3350)  
                       at android.app.ActivityThread.access$1100(ActivityThread.java:222)  
                       at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1795)  
                       at android.os.Handler.dispatchMessage(Handler.java:102)  
                       at android.os.Looper.loop(Looper.java:158)  
                       at android.app.ActivityThread.main(ActivityThread.java:7229)  
                       at java.lang.reflect.Method.invoke(Native Method)  
                       at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1230)  
                       at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1120)  

：

String workout3 = args.getString("workout"); 

WorkoutDaysActivity.java:47この行です：

WedFragment wedFragment = new WedFragment(); 

およびWorkoutDaysActivity.java:27は次の行です。

tabLayout.setupWithViewPager(vp); 

Answer 1

あなたのonCreate関数内でこれらの2行を置き：

public class WedFragment extends Fragment { 

Bundle args; 
String workout3=""; 

@Nullable 
@Override 
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) { 
    args = getArguments(); 
    workout3 = args.getString("workout"); 
    View view = inflater.inflate(R.layout.wed_fragment, null); 

    //RECYCLERVIEW 
    RecyclerView rv = (RecyclerView) view.findViewById(R.id.mRecyclerWed); 
    rv.setLayoutManager(new LinearLayoutManager(this.getActivity())); 
    rv.setAdapter(new MyRecyclerAdapter(this.getActivity(), getWedWorkout())); 

    return view; 
}