片段中的ViewPager在返回时丢失内容

我正在实施tabhost使用FragmentActivity ,在第一个选项卡下我加载一个包含一个CirclePageIndIcatorCirclePageIndIcator的欢迎片段,我需要加载4个视图在CirclePageIndIcator

这是我的WelcomeFragment

 public class WelcomeFragment extends Fragment { PageAdapter mAdapter; ViewPager mPager; CirclePageIndicator mIndicator; List<Fragment> fragments; @Override public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) { View view = inflater.inflate(R.layout.frag_welcome_layout,null); mPager=(ViewPager)view.findViewById(R.id.myViewPager); mIndicator=(CirclePageIndicator)view.findViewById(R.id.circlePageIndicator1); fragments=new ArrayList<Fragment>(); return view; } @Override public void onActivityCreated(Bundle savedInstanceState) { super.onActivityCreated(savedInstanceState); Fragment fragment; for(int i=0;i<4;i++) { fragment= Fragment.instantiate(getActivity(), TipsFragment.class.getName()); fragments.add(fragment); } mAdapter = new PageAdapter(getFragmentManager(),fragments); mPager.setAdapter(mAdapter); mIndicator.setViewPager(mPager); } } 

这是我的页面适配器

 public class PageAdapter extends FragmentPagerAdapter implements Serializable{ List<Fragment> fragments; public PageAdapter(FragmentManager fm,List<Fragment> frags) { super(fm); fragments = frags; } @Override public Fragment getItem(int arg0) { // TODO Auto-generated method stub return TipsFragment.newInstance(0, 0); } @Override public int getCount() { // TODO Auto-generated method stub return 4; } @Override public void destroyItem(ViewGroup container, int position, Object object) { FragmentManager manager = ((Fragment) object).getFragmentManager(); FragmentTransaction trans = manager.beginTransaction(); trans.remove((Fragment) object); trans.commit(); super.destroyItem(container, position, object); } } 

当我加载应用程序首先tabFragmentActivity加载成功和welcomepragment内的viewpager工作正常,但是当我移动到第二个选项卡再次返回到第一个选项卡ViewPager不会成功加载。

我该如何解决?

根据我使用getChildFragmentManager的build议,但应用程序在logcat中有崩溃错误

 09-09 13:28:39.412: E/AndroidRuntime(3100): FATAL EXCEPTION: main 09-09 13:28:39.412: E/AndroidRuntime(3100): java.lang.IllegalStateException: No activity 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1091) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1086) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.dispatchActivityCreated(FragmentManager.java:1877) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.Fragment.performActivityCreated(Fragment.java:1492) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:947) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.moveToState(FragmentManager.java:1104) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.BackStackRecord.run(BackStackRecord.java:682) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl.execPendingActions(FragmentManager.java:1460) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.support.v4.app.FragmentManagerImpl$1.run(FragmentManager.java:440) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.os.Handler.handleCallback(Handler.java:725) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.os.Handler.dispatchMessage(Handler.java:92) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.os.Looper.loop(Looper.java:137) 09-09 13:28:39.412: E/AndroidRuntime(3100): at android.app.ActivityThread.main(ActivityThread.java:5041) 09-09 13:28:39.412: E/AndroidRuntime(3100): at java.lang.reflect.Method.invokeNative(Native Method) 09-09 13:28:39.412: E/AndroidRuntime(3100): at java.lang.reflect.Method.invoke(Method.java:511) 09-09 13:28:39.412: E/AndroidRuntime(3100): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:793) 09-09 13:28:39.412: E/AndroidRuntime(3100): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:560) 09-09 13:28:39.412: E/AndroidRuntime(3100): at dalvik.system.NativeStart.main(Native Method 

Solutions Collecting From Web of "片段中的ViewPager在返回时丢失内容"

如果您在Fragment中使用ViewPager ,则在创build新适配器时,应该使用ChildFragmentManager

 getChildFragmentManager() 

尝试这个:

  ViewPager pager = [your viewPAger] pager.setOffscreenPageLimit([quantity of tabs that you are going to use]); 

使用该句子(pager.setOffscreenPageLimit),您可以指定选项卡在被ViewPager擦除之前能够保持多远!

干杯!

使用AsyncTask来设置ViewPagerAdapter:

 private class SetAdapterTask extends AsyncTask<Void, Void, Void> { protected Void doInBackground(Void... params) { return null; } @Override protected void onPostExecute(Void result) { if(mPagerAdapter != null) mViewPager.setAdapter(mPagerAdapter); } } 

像这样调用它:

 mAdapter = new PageAdapter(getChildFragmentManager(), fragments); new SetAdapterTask().execute(); 

而不是调用:

 mViewPager.setAdapter(mPagerAdapter); 

并在onCreateView(...)方法中设置适配器而不是 onActivityCreated(...).

另外, 使用getChildFragmentManager()而不是getFragmentManager()。