스 와이프 조각 내기 3 동작

Question

ViewPager 조각을 사용하여 스 와이프 할 수있는 3 가지 작업을 수행하고 있습니다. 하지만 스크립트를 실행하면 다음과 같은 오류가 발생합니다. 아무도 나에게 오류 로그를 설명 할 수 없다. 스 와이프 조각 활동을하고 있습니다.

오류 :

07-17 14:48:29.421: W/dalvikvm(18204): threadid=1: thread exiting with uncaught exception (group=0x41723c08) 
07-17 14:48:29.431: E/AndroidRuntime(18204): FATAL EXCEPTION: main 
07-17 14:48:29.431: E/AndroidRuntime(18204): Process: kids.math.newmathforkids, PID: 18204 
07-17 14:48:29.431: E/AndroidRuntime(18204): java.lang.NullPointerException 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.app.BackStackRecord.doAddOp(BackStackRecord.java:394) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.app.BackStackRecord.add(BackStackRecord.java:389) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.app.FragmentPagerAdapter.instantiateItem(FragmentPagerAdapter.java:99) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.view.ViewPager.addNewItem(ViewPager.java:837) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.view.ViewPager.populate(ViewPager.java:987) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.view.ViewPager.populate(ViewPager.java:919) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1441) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.View.measure(View.java:17478) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.widget.RelativeLayout.measureChildHorizontal(RelativeLayout.java:719) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.widget.RelativeLayout.onMeasure(RelativeLayout.java:455) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.View.measure(View.java:17478) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5363) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.View.measure(View.java:17478) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5363) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at com.android.internal.widget.ActionBarOverlayLayout.onMeasure(ActionBarOverlayLayout.java:412) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.View.measure(View.java:17478) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5363) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.widget.FrameLayout.onMeasure(FrameLayout.java:310) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2548) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.View.measure(View.java:17478) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2285) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1396) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1595) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1254) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:6624) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.Choreographer$CallbackRecord.run(Choreographer.java:812) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.Choreographer.doCallbacks(Choreographer.java:612) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.Choreographer.doFrame(Choreographer.java:582) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:798) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.os.Handler.handleCallback(Handler.java:733) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.os.Handler.dispatchMessage(Handler.java:95) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.os.Looper.loop(Looper.java:146) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at android.app.ActivityThread.main(ActivityThread.java:5602) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at java.lang.reflect.Method.invokeNative(Native Method) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at java.lang.reflect.Method.invoke(Method.java:515) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1283) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1099) 
07-17 14:48:29.431: E/AndroidRuntime(18204): at dalvik.system.NativeStart.main(Native Method) 
07-17 14:48:29.451: W/ActivityManager(1183): Force finishing activity kids.math.newmathforkids/.level_selection 
07-17 14:48:29.461: W/ActivityManager(1183): Force finishing activity kids.math.newmathforkids/.MainActivity 

활동

public class level_selection extends FragmentActivity { 
MyPageAdapter pageAdapter; 
@Override 
public void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.level_selection); 

    List<Fragment> fragments = getFragments(); 

    pageAdapter = new MyPageAdapter(getSupportFragmentManager(), fragments); 

    ViewPager pager = (ViewPager)findViewById(R.id.viewpager); 
    pager.setAdapter(pageAdapter); 

} 

private List<Fragment> getFragments(){ 
List<Fragment> fList = new ArrayList<Fragment>(); 

fList.add(level_selection_easy.newInstance("Fragment 1")); 
fList.add(level_selection_normal.newInstance("Fragment 2")); 
fList.add(level_selection_medium.newInstance("Fragment 3")); 

return fList; 
} 

private class MyPageAdapter extends FragmentPagerAdapter { 
private List<Fragment> fragments; 

    public MyPageAdapter(FragmentManager fm, List<Fragment> fragments) { 
     super(fm); 
     this.fragments = fragments; 
    } 
    @Override 
    public Fragment getItem(int position) { 
     return this.fragments.get(position); 
    } 

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

조각 활동 :

public class level_selection_easy extends Fragment { 

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


// Create UI components here. 

     return v; 
    } 

public static Fragment newInstance(String string) { 
    // TODO Auto-generated method stub 
    return null; 
} 
} 

Answer 1

public static Fragment newInstance(String string) { 
    // TODO Auto-generated method stub 
    return null; <-- Error 
} 

또는으로 변경합니다.

fList.add(new level_selection_easy()); 
fList.add(new level_selection_normal()); 
fList.add(new level_selection_medium());