просмотр пейджера с SQLite в android

Question

Я хочу показать только ограниченные страницы в ViewPager. Я получаю и получаю строку подсчета из таблицы SQLite, используя следующий запрос.

Cursor cursor2 = db.rawQuery("select count(activityObjId) from ActivityObjectList where " + "activityId" + " = ?", new String[]{strDescription}); 

count(activityObjId) My 2, поэтому я хочу, чтобы добавить 2 изображения в ViewPager. count(activityObjId) - 5, поэтому я хочу добавить 5 изображений в ViewPager. Может кто-то помочь, как решить эту проблему. Я пробовал, но получал ошибку.

08-06 06:00:04.744 11207-11207/? E/AndroidRuntime﹕ FATAL EXCEPTION: main 
    java.lang.IllegalStateException: The application's PagerAdapter changed the adapter's contents without calling PagerAdapter#notifyDataSetChanged! Expected adapter item count: 0, found: 1 Pager id: com.example.tazeen.classnkk:id/Image_ViewPagers Pager class: class android.support.v4.view.ViewPager Problematic adapter: class com.example.tazeen.classnkk.AllPosts_Page$MyPagerAdapter 
      at android.support.v4.view.ViewPager.populate(ViewPager.java:999) 
      at android.support.v4.view.ViewPager.populate(ViewPager.java:951) 
      at android.support.v4.view.ViewPager.onMeasure(ViewPager.java:1473) 
      at android.view.View.measure(View.java:15848) 
      at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012) 
      at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404) 
      at android.widget.LinearLayout.measureVertical(LinearLayout.java:695) 
      at android.widget.LinearLayout.onMeasure(LinearLayout.java:588) 
      at android.view.View.measure(View.java:15848) 
      at android.view.ViewGroup.measureChildWithMargins(ViewGroup.java:5012) 
      at android.widget.LinearLayout.measureChildBeforeLayout(LinearLayout.java:1404) 
      at android.widget.LinearLayout.measureVertical(LinearLayout.java:695) 
      at android.widget.LinearLayout.onMeasure(LinearLayout.java:588) 
      at android.view.View.measure(View.java:15848) 
      at android.widget.ListView.setupChild(ListView.java:1918) 
      at android.widget.ListView.makeAndAddView(ListView.java:1843) 
      at android.widget.ListView.fillDown(ListView.java:675) 
      at android.widget.ListView.fillFromTop(ListView.java:736) 
      at android.widget.ListView.layoutChildren(ListView.java:1655) 
      at android.widget.AbsListView.onLayout(AbsListView.java:2012) 
      at android.view.View.layout(View.java:14289) 
      at android.view.ViewGroup.layout(ViewGroup.java:4562) 
      at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671) 
      at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525) 
      at android.widget.LinearLayout.onLayout(LinearLayout.java:1434) 
      at android.view.View.layout(View.java:14289) 
      at android.view.ViewGroup.layout(ViewGroup.java:4562) 
      at android.widget.FrameLayout.onLayout(FrameLayout.java:448) 
      at android.view.View.layout(View.java:14289) 
      at android.view.ViewGroup.layout(ViewGroup.java:4562) 
      at android.widget.LinearLayout.setChildFrame(LinearLayout.java:1671) 
      at android.widget.LinearLayout.layoutVertical(LinearLayout.java:1525) 
      at android.widget.LinearLayout.onLayout(LinearLayout.java:1434) 
      at android.view.View.layout(View.java:14289) 
      at android.view.ViewGroup.layout(ViewGroup.java:4562) 
      at android.widget.FrameLayout.onLayout(FrameLayout.java:448) 
      at android.view.View.layout(View.java:14289) 
      at android.view.ViewGroup.layout(ViewGroup.java:4562) 
      at android.view.ViewRootImpl.performLayout(ViewRootImpl.java:1976) 
      at android.view.ViewRootImpl.performTraversals(ViewRootImpl.java:1730) 
      at android.view.ViewRootImpl.doTraversal(ViewRootImpl.java:1004) 
      at android.view.ViewRootImpl$TraversalRunnable.run(ViewRootImpl.java:5481) 
      at android.view.Choreographer$CallbackRecord.run(Choreographer.java:749) 
      at android.view.Choreographer.doCallbacks(Choreographer.java:562) 
      at android.view.Choreographer.doFrame(Choreographer.java:532) 
      at android.view.Choreographer$FrameDisplayEventReceiver.run(Choreographer.java:735) 
      at android.os.Handler.handleCallback(Handler.java:730) 
      at android.os.Handler.dispatchMessage(Handler.java:92) 
      at android.os.Looper.loop(Looper.java:137) 
      at android.app.ActivityThread.main(ActivityThread.java:5103) 
      at java.lang.reflect.Method.invokeNative(Native Method) 
      at java.lang.reflect.Method.invoke(Method.java:525) 
      at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:737) 
      at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:553) 
      at dalvik.system.NativeStart.main(Native Method) 

Моя активность Код

public void getActivityObjectId_Count() { 
     try { 
      dbhelper = new MyDbHelper(this); 
      SQLiteDatabase db = dbhelper.getReadableDatabase(); 


      Cursor cursor2 = db.rawQuery("select count(activityObjId) from ActivityObjectList where " + "activityId" + " = ?", new String[]{strDescription}); 
      if (cursor2 != null) { 

       cursor2.moveToFirst(); 

       String strCount_ActivityObjectId = cursor2.getString(0); 
       intCount = Integer.parseInt(strCount_ActivityObjectId); 

       Log.e("Count", "in getActivityObjectId = " + strCount_ActivityObjectId); 
       Log.e("intCount convert ","to = " + intCount); 

      } 

      cursor2.close(); 
      db.close(); 
     } catch (Exception e) { 
      // TODO: handle exception 
      e.printStackTrace(); 
     } 

    } 

класс MyPagerAdapter расширяет PagerAdapter {

Context mContent; 
    LayoutInflater mLayoutInflater; 
    private List<String> testImages = new ArrayList<String>(); 


    private int[] GalImages = new int[]{ 
      R.drawable.img_placeholder, 
      R.drawable.img_placeholder, 
      R.drawable.img_placeholder, 
      R.drawable.img_placeholder, 
      R.drawable.img_placeholder, 
      R.drawable.img_placeholder 
    }; 


    public MyPagerAdapter(Context context) { 
     super(); 
     mContent = context; 

     mLayoutInflater = (LayoutInflater) mContent.getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
    } 

    @Override 
    public float getPageWidth(int position) { 
     return 0.9f; 
    } 

    @Override 
    public Object instantiateItem(ViewGroup container, int position) { 
     // TODO Auto-generated catch block 

     ImageView imageView = new ImageView(mContent); 
     imageView.setLayoutParams(new ViewGroup.LayoutParams(ViewGroup.LayoutParams.FILL_PARENT, ViewGroup.LayoutParams.FILL_PARENT)); 
     imageView.setScaleType(ImageView.ScaleType.FIT_XY); 


     imageView.setImageResource(GalImages[position]); 

     ((ViewPager) container).addView(imageView, 0); 
     return imageView; 

    } 

    @Override 
    public void destroyItem(ViewGroup container, int position, Object object) { 
     ((ViewPager) container).removeView((View) object); 
    } 

    @Override 
    public int getCount() { 

       return intCount; 
    } 

    @Override 
    public boolean isViewFromObject(View view, Object obj) { 

     return view == ((ImageView) obj); 
    } 

} 

Благодаря передовой.

Answer 1

Кажется, вы вернули неверный счет страницы в ViewPager. Вы должны вернуть фактический номер страницы в свой метод getCount(). В этом случае вы должны вернуть количество изображений, которые вы добавили в ViewPager.