Question

我正在使用带有FragmentStatePagerAdapter的NaviagtionDrawer。当我在NavigationDrawer中切换到第二个选项时，PagerAdapter强制关闭。

堆栈跟踪：

10-25 17:25:25.518: W/dalvikvm(1788): threadid=1: thread exiting with uncaught exception (group=0x2b542210)
10-25 17:25:25.538: E/AndroidRuntime(1788): FATAL EXCEPTION: main
10-25 17:25:25.538: E/AndroidRuntime(1788): java.lang.NullPointerException
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.support.v4.app.Fragment.setUserVisibleHint(Fragment.java:819)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.support.v4.app.FragmentStatePagerAdapter.setPrimaryItem(FragmentStatePagerAdapter.java:152)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.support.v4.view.ViewPager.populate(ViewPager.java:1066)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.support.v4.view.ViewPager.populate(ViewPager.java:914)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.support.v4.view.ViewPager$3.run(ViewPager.java:244)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.os.Handler.handleCallback(Handler.java:605)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.os.Handler.dispatchMessage(Handler.java:92)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.os.Looper.loop(Looper.java:137)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at android.app.ActivityThread.main(ActivityThread.java:4441)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at java.lang.reflect.Method.invokeNative(Native Method)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at java.lang.reflect.Method.invoke(Method.java:511)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:784)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:551)
10-25 17:25:25.538: E/AndroidRuntime(1788):     at dalvik.system.NativeStart.main(Native Method)

代码：

     private void selectItem(int position) {
    // update the main content by replacing fragments
    PlanetFragment fragment = new PlanetFragment();
   // Bundle args = new Bundle();
   // args.putInt(PlanetFragment.ARG_PLANET_NUMBER, position);
    //fragment.setArguments(args);


    android.support.v4.app.FragmentManager fragmentManager = getSupportFragmentManager();
    android.support.v4.app.FragmentTransaction fragmentTransaction =          fragmentManager.beginTransaction();

    fragmentTransaction.replace(R.id.myfivepanelpager, fragment);
    fragmentTransaction.commit();

    // update selected item and t itle, then close the drawer
    mDrawerList.setItemChecked(position, true);
    setTitle(mPlanetTitles[position]);
    mDrawerLayout.closeDrawer(mDrawerList);
}

NaviagtionDrawer OncreateView

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

        return rootView;
    }

FragmentStatePagerAdapter OncreateView

     public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.item_pager, container, false);

        final ViewHolder holder = new ViewHolder();
        holder.imageView = (ImageView)rootView. 
                findViewById(R.id.imageView1);
        holder.progressBar=(ProgressBar)rootView.findViewById(R.id.progressBar1);


              //some code for swiping pages }}

使用fragmentpageradapter时获取nullpointer异常？

0 个答案: