【发布时间】：2017-01-07 10:11:40
【问题描述】：
我正在使用view pager 实现tablayout，在我的场景中我有两个tab。在我的第一个tab 中，我添加了存储在share preference 中的数据。当我移动到第二个选项卡时，应该从share preference 检索数据并显示在listview 中。当我从我的第一个 tab 添加数据时，数据已成功添加但未在我的第二个 tab 中显示意味着我必须关闭我的应用程序并再次重新启动应用程序，以便我可以看到从我的第一个保存的详细信息tab。
下面是我的活动代码。
public class FragmentExample extends AppCompatActivity {
private ViewPagerAdapter viewPagerAdapter;
@BindView(R.id.tabCountryState)
TabLayout tabCountryState;
@BindView(R.id.viewPager)
ViewPager viewPager;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_fragment_example);
ButterKnife.bind(this);
setViewPager();
setTabIcon();
viewPager.setOffscreenPageLimit(2);
tabCountryState.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
@Override
public void onTabSelected(TabLayout.Tab tab) {
Log.e("Current tab is ", "===> " + tab.getPosition());
}
@Override
public void onTabUnselected(TabLayout.Tab tab) {
}
@Override
public void onTabReselected(TabLayout.Tab tab) {
}
});
}
private void setViewPager() {
// set Adaapter.
viewPagerAdapter = new ViewPagerAdapter(getSupportFragmentManager(), FragmentExample.this);
viewPager.setAdapter(viewPagerAdapter);
tabCountryState.setupWithViewPager(viewPager);
}
// set custom icon to tab in Tablayout.
private void setTabIcon() {
// First Tab
View firstTab = (View) LayoutInflater.from(this).inflate(R.layout.tab_icon_first, null);
TextView tvFirsIcon = ButterKnife.findById(firstTab, R.id.tvFirsIcon);
tvFirsIcon.setText("First Tab");
tabCountryState.getTabAt(0).setCustomView(firstTab);
// First Tab
View secondTab = (View) LayoutInflater.from(this).inflate(R.layout.tab_icon_second, null);
TextView tvSecondIcon = ButterKnife.findById(secondTab, R.id.tvSecondIcon);
tvSecondIcon.setText("Second Tab");
tabCountryState.getTabAt(1).setCustomView(secondTab);
}
public class ViewPagerAdapter extends FragmentStatePagerAdapter {
private Context context;
private FirstFragment firstFragment;
private SecondFragment secondFragment;
public ViewPagerAdapter(FragmentManager fm, Context mainActivity) {
super(fm);
context = mainActivity;
new FirstFragment();
}
@Override
public Fragment getItem(int position) {
switch (position) {
case 0:
firstFragment = new FirstFragment();
return firstFragment;
case 1:
secondFragment = new SecondFragment();
return secondFragment;
default:
return null;
}
}
@Override
public int getCount() {
return 2;
}
@Override
public CharSequence getPageTitle(int position) {
return " " + position;
}
}
}
这是我将数据添加到共享偏好中的 FirstFragment。
public class FirstFragment extends Fragment {
private View v;
@BindView(R.id.btnSubmit)
Button btnSubmit;
@BindView(R.id.edtCityName)
EditText edtCityName;
@BindView(R.id.spStateName)
Spinner spStateName;
private Unbinder unbinder;
private ArrayList<String> alStateName;
private ArrayList<AllStateCityModel> alAllStateCity;
private SpinnerStateAdapter spinnerAdapter;
private int spinnerPosition;
private String strCityName, strSpinnerValue;
@OnClick(R.id.btnSubmit)
public void submit(View view) {
if (spinnerPosition !=0) {
strCityName = edtCityName.getText().toString().trim();
alAllStateCity = SessinoManager.getCityList(getActivity());
if (strCityName.length() > 0) {
alAllStateCity.get(spinnerPosition).getAlCityName().add(new CityStateModel(strCityName));
} else {
}
// Save new data to Session.
SessinoManager.saveCityList(getActivity(), alAllStateCity);
SecondFragment.cityAdapter.notifyDataSetChanged();
Toast.makeText(getActivity(), "Detail saved successfully ", Toast.LENGTH_SHORT).show();
edtCityName.setText("");
} else {
Toast.makeText(getActivity(), "Please select state", Toast.LENGTH_SHORT).show();
}
}
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Bundle args = getArguments();
v = inflater.inflate(R.layout.fragment_first, container, false);
unbinder = ButterKnife.bind(this, v);
// arraylist checking if data is available into session.
if(SessinoManager.getCityList(getActivity()).size()>0){
Log.e("First fragment "," if condition ");
alAllStateCity = SessinoManager.getCityList(getActivity());
alStateName = new ArrayList<>();
for(int i=0;i<alAllStateCity.size();i++){
alStateName.add(alAllStateCity.get(i).getStrStateName());
}
setStateSpinner();
}else{
loadArraylist();
setStateSpinner();
}
return v;
}
private void setStateSpinner() {
spStateName.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
spinnerPosition = i;
spinnerAdapter.notifyDataSetChanged();
strSpinnerValue = alStateName.get(i).toString().trim();
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
spinnerAdapter = new SpinnerStateAdapter(getActivity(), alStateName);
spStateName.setAdapter(spinnerAdapter);
}
private void loadArraylist() {
alAllStateCity = new ArrayList<>();
alStateName = new ArrayList<>();
alStateName.add(0, "Select State");
alStateName.add("Gujarat");
alStateName.add("Maharashtra");
alStateName.add("Madhya Pradesh");
for (int i = 0; i < alStateName.size(); i++) {
alAllStateCity.add(new AllStateCityModel(alStateName.get(i), alAllStateCity.size(), new ArrayList<CityStateModel>()));
}
SessinoManager.saveCityList(getActivity(), alAllStateCity);
}
@Override public void onDestroyView() {
super.onDestroyView();
unbinder.unbind();
Log.e("First fragment "," on destroy");
}
}
这是我的 SecondFragment，我必须从 Share preference 获取保存的详细信息。
public class SecondFragment extends Fragment {
private View v;
private Unbinder unbinder;
@BindView(R.id.lvCityList)
ListView lvCityList;
@BindView(R.id.spinnerStateName)
Spinner spinnerStateName;
private ArrayList<AllStateCityModel> alAllStateCity;
private ArrayList<CityStateModel> alCityName;
private ArrayList<String> alStateName;
private int spinnerPosition;
private SpinnerStateAdapter spinnerAdapter;
private ArrayList<String> alCity;
public static CityAdapter cityAdapter;
private Context context;
@Nullable
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
Bundle args = getArguments();
v = inflater.inflate(R.layout.fragment_two, container, false);
unbinder = ButterKnife.bind(this, v);
context = getActivity();
loadArrayList(context);
Log.e("onCreateView", "onCreateView");
return v;
}
private void loadArrayList(Context context) {
alCityName = new ArrayList<>();
alStateName = new ArrayList<>();
alAllStateCity = SessinoManager.getCityList(context);
for (int j = 0; j < alAllStateCity.size(); j++) {
// Log.e("State name "," =========================> "+allPlayList.get(j).getStrStateName());
// get state name from session
alStateName.add(alAllStateCity.get(j).getStrStateName());
setSpinner(context);
}
}
private void setSpinner(Context context) {
spinnerAdapter = new SpinnerStateAdapter(context, alStateName);
spinnerStateName.setAdapter(spinnerAdapter);
spinnerStateName.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
@Override
public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
spinnerPosition = i;
spinnerAdapter.notifyDataSetChanged();
setList(spinnerPosition);
}
@Override
public void onNothingSelected(AdapterView<?> adapterView) {
}
});
}
private void setList(int position) {
alCityName = alAllStateCity.get(position).getAlCityName();
alCity = new ArrayList<>();
for (int i = 0; i < alCityName.size(); i++) {
// Log.e("City name "," !!!!!!!!!!!!!!!!"+alCityName.get(i).getStrCity());
alCity.add(alCityName.get(i).getStrCity());
}
cityAdapter = new CityAdapter(context, alCity);
lvCityList.setAdapter(cityAdapter);
cityAdapter.notifyDataSetChanged();
}
}
我正在将数据保存到下面给出的Share preference。
public class SessinoManager {
private static final String CITY_PREFERENCE = "city_preference";
// Save data to share preference.
public static void saveCityList(Context context, ArrayList<AllStateCityModel> alAllPlayList) {
try {
SharedPreferences settings;
SharedPreferences.Editor editor;
settings = context.getSharedPreferences(CITY_PREFERENCE,Context.MODE_PRIVATE);
editor = settings.edit();
Gson gson = new Gson();
String jsonUsers = gson.toJson(alAllPlayList);
editor.putString("all_play_list", jsonUsers);
editor.commit();
// Check to save data into share preferent
for(int j=0;j<alAllPlayList.size();j++){
Log.e("State name ","----------------------"+alAllPlayList.get(j).getStrStateName());
ArrayList<CityStateModel> cityName = alAllPlayList.get(j).getAlCityName();
for(int i=0;i<cityName.size();i++){
Log.e("cityName "," in session ==> "+cityName.get(i).getStrCity());
}
}
} catch (Exception e) {
e.printStackTrace();
}
}
public static ArrayList<AllStateCityModel> getCityList(Context context)
{
SharedPreferences settings;
List<AllStateCityModel> users = new ArrayList<>();
settings = context.getSharedPreferences(CITY_PREFERENCE,Context.MODE_PRIVATE);
if (settings.contains("all_play_list"))
{
String jsonUsers = settings.getString("all_play_list", null);
Gson gson = new Gson();
AllStateCityModel[] userItems = gson.fromJson(jsonUsers,AllStateCityModel[].class);
users = Arrays.asList(userItems);
users= new ArrayList<AllStateCityModel>(users);
}
return (ArrayList<AllStateCityModel>) users;
}
}
当我在第一个选项卡中添加新的城市详细信息时，数据是数据成功，但是当我滑动或移动到下一个时，数据没有显示，我必须重新启动整个应用程序才能从 Share preference. 获取更新的数据请帮我解决这个问题。提前致谢。
【问题讨论】：
标签： android android-fragments android-viewpager sharedpreferences android-tablayout