当项目被点击时维护列表视图状态

Question

我有一个片段（父），它包含一个带有两个选项卡的tabhost。每个选项卡是一个包含listview的片段。当第一次访问父片段时，两个listview片段加载好，如下所示。

问题是，当eaither的ListView项是clicked.After被重定向到被点击的项目的详细信息，在按下后退按钮两个列表视图是空的，不再displayed.Here是我意思是

我想显示列表视图就像他们之前我点击一个item.How我可以实现这一点？建议将高度赞赏。 为每两个片段的代码：

public class AvailableDriversFragment extends Fragment implements 
    OnItemClickListener, OnScrollListener { 
ProgressDialog progressDialog; 
ArrayList<Driver> adverts; 
TextView loadingmore; 

// products JSONArray 
JSONArray products = null; 

// JSON Node names 
private static final String TAG_SUCCESS = "success"; 
private static final String TAG_COUNT = "count"; 
private static final String TAG_PRODUCTS = "products"; 
private static final String TAG_FNAME = "first_name"; 
private static final String TAG_ONAME = "other_names"; 
private static final String TAG_BRIEF = "description"; 
private static final String TAG_ID = "driver_id"; 
private static final String TAG_LOCATION = "location"; 
private static final String TAG_PHONE = "phone"; 
private static final String TAG_CLASSA = "classA"; 
private static final String TAG_CLASSB = "classB"; 
private static final String TAG_CLASSC = "classC"; 
private static final String TAG_CLASSD = "classD"; 
private static final String TAG_CLASSE = "classE"; 

// Bundle key names 
private static final String KEY_ID = "advert_id"; 
private static final String KEY_LOCATION = "advert_location"; 
private static final String KEY_NAME = "advert_name"; 
private static final String KEY_BRIEF = "advert_brief"; 
private static final String KEY_PHONE = "advert_phone"; 

ListView driverslist; 
Driver advert; 

boolean loadingMore; 
int currentPage; 
int itemCount; 

public AvailableDriversFragment() { 
    advert = new Driver(); 
    loadingMore = false; 
    currentPage = 0; 
    itemCount = 0; 
} 

public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 
    setRetainInstance(true); 

    View rootView = inflater.inflate(R.layout.fragment_availabledrivers, 
      container, false); 

    driverslist = (ListView) rootView 
      .findViewById(R.id.listView_availabledrivers); 
    loadingmore = (TextView) rootView 
      .findViewById(R.id.availabledrivers_textView_more); 
    if (savedInstanceState != null) { 
     currentPage = savedInstanceState.getInt("currentPage"); 
     itemCount = savedInstanceState.getInt("itemCount"); 
     Log.i("currentPage", "" + currentPage); 
     driverslist.setAdapter(new DriversListAdapter(getActivity(), 
       adverts)); 

    } else { 
     new GetDrivers().execute(); 
    } 

    driverslist.setOnItemClickListener(this); 
    driverslist.setOnScrollListener(this); 
    return rootView; 
} 

@Override 
public void onItemClick(AdapterView<?> parent, View view, int position, 
     long id) { 
    Fragment detailsFragment = new DriverDetailsFragment(); 
    advert = (Driver) parent.getItemAtPosition(position); 
    int advert_id = advert.getId(); 
    String advert_location = advert.getLocation(); 
    String advert_brief = advert.getBrief(); 
    String advert_name = advert.getName(); 

    Bundle bundle = new Bundle(); 
    bundle.putInt(KEY_ID, advert_id); 
    bundle.putString(KEY_LOCATION, advert_location); 
    bundle.putString(KEY_NAME, advert_name); 
    bundle.putString(KEY_BRIEF, advert_brief); 

    detailsFragment.setArguments(bundle); 

    FragmentManager fragmentManager = getActivity() 
      .getSupportFragmentManager(); 
    fragmentManager.beginTransaction() 
      .replace(R.id.content_frame, detailsFragment) 
      .addToBackStack("latest").commit(); 

} 
} 

第二个片段：

public class DriverJobsFragment extends Fragment implements 
    OnItemClickListener, OnScrollListener { 
ProgressDialog progressDialog; 
ArrayList<CarItem> adverts; 
TextView loadingmore; 

// products JSONArray 
JSONArray products = null; 

// JSON Node names 
private static final String TAG_SUCCESS = "success"; 
private static final String TAG_COUNT = "count"; 
private static final String TAG_PRODUCTS = "products"; 
private static final String TAG_HEADING = "tag"; 
private static final String TAG_DESCRIPTION = "description"; 
private static final String TAG_PRICE = "price"; 
private static final String TAG_ID = "item_id"; 
private static final String TAG_LOCATION = "location"; 
private static final String TAG_PHOTO = "photo"; 
private static final String TAG_MODEL = "model"; 
private static final String TAG_MAKE = "make"; 
private static final String TAG_REGISTRATION = "registration"; 
private static final String TAG_CATEGORY = "category"; 
private static final String TAG_TRANSMISSION = "transmission"; 
private static final String TAG_FUEL = "fuel"; 
private static final String TAG_ENGINE = "engine_size"; 
private static final String TAG_PHONE = "phone"; 

// Bundle key names 
private static final String KEY_DESCRIPTION = "advert_description"; 
private static final String KEY_ID = "advert_id"; 
private static final String KEY_RATE = "advert_rate"; 
private static final String KEY_LOCATION = "advert_location"; 
private static final String KEY_FUEL = "advert_fuel"; 
private static final String KEY_ENGINE = "advert_engine"; 
private static final String KEY_MODEL = "advert_model"; 
private static final String KEY_MAKE = "advert_make"; 
private static final String KEY_TRANSMISSION = "advert_transmission"; 
private static final String KEY_REGISTRATION = "advert_registration"; 
private static final String KEY_CATEGORY = "advert_category"; 
private static final String KEY_PHONE = "advert_phone"; 

ListView jobslist; 
CarItem advert; 

boolean loadingMore; 
int currentPage; 
int itemCount; 

public DriverJobsFragment() { 
    advert = new CarItem(); 
    loadingMore = false; 
    currentPage = 0; 
    itemCount = 0; 
} 

@Override 
public View onCreateView(LayoutInflater inflater, ViewGroup container, 
     Bundle savedInstanceState) { 
    setRetainInstance(true); 

    View rootView = inflater.inflate(R.layout.fragment_driverjobs, 
      container, false); 

    jobslist = (ListView) rootView.findViewById(R.id.listView_driverjobs); 
    loadingmore = (TextView) rootView 
      .findViewById(R.id.driverjobs_textView_more); 
    if (savedInstanceState != null) { 
     currentPage = savedInstanceState.getInt("currentPage"); 
     itemCount = savedInstanceState.getInt("itemCount"); 
     Log.i("currentPage", "" + currentPage); 
     jobslist.setAdapter(new CarsListAdapter(getActivity(), adverts)); 
    } else { 
     new GetDriverJobs().execute(); 
    } 

    jobslist.setOnItemClickListener(this); 
    jobslist.setOnScrollListener(this); 
    return rootView; 
} 

@Override 
public void onItemClick(AdapterView<?> parent, View view, int position, 
     long id) { 
    Fragment detailsFragment = new DriverJobDetailsFragment(); 
    advert = (CarItem) parent.getItemAtPosition(position); 
    int advert_id = advert.getId(); 
    String advert_description = advert.getDescription(); 
    String advert_location = advert.getLocation(); 
    String advert_price = advert.getPrice(); 
    String advert_engine = advert.getEngineSize(); 
    String advert_model = advert.getModel(); 
    String advert_make = advert.getMake(); 
    String advert_transmission = advert.getTransmission(); 
    String advert_fuel = advert.getFuel(); 
    String advert_registration = advert.getRegistration(); 
    String advert_category = advert.getCategeory(); 
    String advert_phone = advert.getPhone(); 

    Bundle bundle = new Bundle(); 
    bundle.putString(KEY_DESCRIPTION, advert_description); 
    bundle.putInt(KEY_ID, advert_id); 
    bundle.putString(KEY_RATE, advert_price); 
    bundle.putString(KEY_LOCATION, advert_location); 
    bundle.putString(KEY_ENGINE, advert_engine); 
    bundle.putString(KEY_MODEL, advert_model); 
    bundle.putString(KEY_MAKE, advert_make); 
    bundle.putString(KEY_TRANSMISSION, advert_transmission); 
    bundle.putString(KEY_FUEL, advert_fuel); 
    bundle.putString(KEY_REGISTRATION, advert_registration); 
    bundle.putString(KEY_CATEGORY, advert_category); 
    bundle.putString(KEY_PHONE, advert_phone); 

    detailsFragment.setArguments(bundle); 

    FragmentManager fragmentManager = getActivity() 
      .getSupportFragmentManager(); 
    fragmentManager.beginTransaction() 
      .replace(R.id.content_frame, detailsFragment) 
      .addToBackStack("jobs_details").commit(); 

} 
} 

和主机片段：

public class DriversFragment extends Fragment implements OnTabChangeListener, 
    OnPageChangeListener { 

private ViewPager mViewPager; 
private DriverTabsAdapter mAdapter; 
private TabHost mTabHost; 

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

    mViewPager = (ViewPager) view.findViewById(R.id.drivers_pager); 

    // Tab Initialization 
    mTabHost = (TabHost) view.findViewById(android.R.id.tabhost); 
    mTabHost.setup(); 

    DriversFragment.AddTab(getActivity(), this.mTabHost, this.mTabHost 
      .newTabSpec("jobs").setIndicator("Driver Jobs")); 
    DriversFragment.AddTab(getActivity(), this.mTabHost, this.mTabHost 
      .newTabSpec("drivers").setIndicator("Drivers")); 
    mAdapter = new DriverTabsAdapter(getActivity() 
      .getSupportFragmentManager()); 
    // Fragments and ViewPager Initialization 
    mTabHost.setOnTabChangedListener(this); 
    mViewPager.setAdapter(mAdapter); 
    mViewPager.setOnPageChangeListener(this); 
    return view; 
} 

// Manages the Tab changes, synchronizing it with Pages 
public void onTabChanged(String tag) { 
    int pos = this.mTabHost.getCurrentTab(); 
    this.mViewPager.setCurrentItem(pos); 
} 

@Override 
public void onPageScrollStateChanged(int arg0) { 
} 

// Manages the Page changes, synchronizing it with Tabs 
@Override 
public void onPageScrolled(int arg0, float arg1, int arg2) { 
    int pos = this.mViewPager.getCurrentItem(); 
    this.mTabHost.setCurrentTab(pos); 
} 

@Override 
public void onPageSelected(int arg0) { 
} 

// Method to add a TabHost 
private static void AddTab(Activity activity, TabHost tabHost, 
     TabHost.TabSpec tabSpec) { 
    tabSpec.setContent(new MyTabFactory(activity)); 
    tabHost.addTab(tabSpec); 
} 

} 

Answer 1

我得到了同样的问题。 这是因为生命周期。当后退按钮被按下时，它会转到onResume（）。 不是onCreateView（）。那是你的问题。 将一些代码移动到onResume（），如listview.setAdpater（adp）。 我希望这会帮助你。

Answer 2

创建一个类并在其中声明静态ArrayList。将所有数据存储在其中并通过它填充ListView。数据将持续到您的应用程序运行时。这种方法可以解决你的问题。