Android PagerAdapter IllegalStateException dans FragmentActivity

Question

Je reçois l'erreur suivante comme ci-dessous et je ne peux pas comprendre pourquoi il se produit. Je n'ai pas plus d'informations sur l'erreur.

J'ai un Android ListView avec 50 articles. Lorsque vous cliquez sur un élément, puis ouvrez le deuxième écran (Fragment Activity avec pager), cette activité Fragment affiche tous les éléments d'un fragment de l'élément cliqué dans ListView jusqu'au dernier élément avec possibilité de glisser à gauche ou à droite.

java.lang.IllegalStateException: 
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1167) 
    at android.support.v4.view.ViewPager.populate(ViewPager.java:1116) 
    at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1642) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1436) 
    at android.widget.LinearLayout.measureVertical(LinearLayout.java:722) 
    at android.widget.LinearLayout.onMeasure(LinearLayout.java:613) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5797) 
    at android.widget.FrameLayout.onMeasure(FrameLayout.java:436) 
    at com.android.internal.policy.impl.PhoneWindow$DecorView.onMeasure(PhoneWindow.java:2910) 
    at android.view.View.measure(View.java:17951) 
    at android.view.ViewRootImpl.performMeasure(ViewRootImpl.java:2048) 
    at android.view.ViewRootImpl.measureHierarchy(ViewRootImpl.java:1185) 
    at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1406) 
    at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1073) 
    at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5988) 
    at android.view.Choreographer$CallbackRecord.run(Choreographer.java:767) 
    at android.view.Choreographer.doCallbacks(Choreographer.java:580) 
    at android.view.Choreographer.doFrame(Choreographer.java:550) 
    at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:753) 
    at android.os.Handler.handleCallback(Handler.java:739) 
    at android.os.Handler.dispatchMessage(Handler.java:95) 
    at android.os.Looper.loop(Looper.java:135) 
    at android.app.ActivityThread.main(ActivityThread.java:5910) 
    at java.lang.reflect.Method.invoke(Native Method:0) 
    at java.lang.reflect.Method.invoke(Method.java:372) 
    at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:1405) 
    at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:1200) 

Answer 1

public class ScreenSlidePagerActivity extends FragmentActivity { 
    /** 
    * The number of pages (wizard steps) to show in this demo. 
    */ 
    public static int NUM_PAGES = 50; 

    /** 
    * The pager widget, which handles animation and allows swiping horizontally to access previous 
    * and next wizard steps. 
    */ 
    private ViewPager mPager; 

    /** 
    * The pager adapter, which provides the pages to the view pager widget. 
    */ 
    private PagerAdapter mPagerAdapter; 

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

     // Instantiate a ViewPager and a PagerAdapter. 
     mPager = (ViewPager) findViewById(R.id.pager); 
     mPagerAdapter = new ScreenSlidePagerAdapter(getSupportFragmentManager()); 
     mPager.setAdapter(mPagerAdapter); 

    } 

    @Override 
    public void onBackPressed() { 
     if (mPager.getCurrentItem() <= 0) { 

      //start an intent 
     } else { 
      // Otherwise, select the previous step. 
      mPager.setCurrentItem(mPager.getCurrentItem() - 1); 
     } 
    } 

    private class ScreenSlidePagerAdapter extends FragmentStatePagerAdapter { 
     public ScreenSlidePagerAdapter(FragmentManager fm) { 
      super(fm); 
     } 

     @Override 
     public Fragment getItem(int position) { 

      Bundle bundle = new Bundle(); 
      bundle.putSerializable("content", "bla bla content"); 

      MyFragment fragmentObj= new MyFragment(); 
      fragmentObj.setArguments(bundle); 
      return fragmentObj; 
     } 

     @Override 
     public int getCount() { 
      return NUM_PAGES; 
     } 

    } 


}