当动态添加的片段在可滑动的标签页中被翻转时，如何从viewpager中的片段中获取数据？

时间：2016-08-03 07:42:57

标签： android

我正在开发一款包含购物功能的应用，并将商品添加到购物车中。 我有导航抽屉。在那里，我有我的第一个片段叫做＆＃34; POSFragment＆＃34;其中我实现了一个viewpager作为要以可滑动tabs形式显示的数据。数据将动态膨胀。所以，我使用了PagerTabStrip和一个viewpager。有一个名为＆＃34; MenuDetailFragment＆＃34;其中数据将通过webservice动态膨胀。此片段的适配器是＆＃34; MenuPagerAdapter＆＃34;。现在，在此片段中，数据将显示在listview中。在每个行中的Listview可以使用递增或递减在每行中加号和减号按钮。在这些按钮之间有textview，其中数量将相应显示。我在两个按钮上都使用了Linkedhashmap，因此，项目和数量保存在linkedhashmap中，然后保存在Sharedpreferences.Its工作正常直到现在。当我在View分页器中滑动并出现下一个片段并且当我点击增量按钮或减少项目上的按钮时，会出现问题。在共享首选项中，它开始保存当前片段项目，之前的片段数据不再存在我已经使用了＆＃34; yourcustomviewpager.setOffscreenPageLimit（3）＆＃34;所以，我可以看到所选项目的数量，我来回扫描，但我使用Linkedhashmap存储在共享偏好中的数据不存在，而是保存当前片段的数据。我希望新数据添加到以前的所有片段中的数据和数据都应该存在。有没有办法这样做？我已经面对这个问题很长一段时间了。任何帮助都会受到赞赏。到目前为止，我已经搜索了很多但没有成功。 以下是一些屏幕截图和相关代码片段。提前预测。

public class PosFragment extends Fragment {
private ViewPager viewPager;
View rootview;
String code;
String name;
String desc;
String rate;
String key;
Button viewCartBtn;
static TextView displayPrice;
static TextView noOfItemsInCart;
RippleView rippleView;
//private sendPosition pos;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
Log.e("oncreateview", "called");
// Inflate the layout for this fragment
rootview = inflater.inflate(R.layout.pos_fragment_layout, container, false);
initViews();
new AsyncTaskGetMenu().execute();
return rootview;
}
public void initViews() {
Log.e("init", "called");
viewPager = (ViewPager) rootview.findViewById(R.id.viewPager);
Button viewCartButton = (Button) rootview.findViewById(R.id.view_cart_btn);
viewPager.setOffscreenPageLimit(3);
viewCartBtn = (Button) rootview.findViewById(R.id.view_cart_btn);
AppMethods.setGlametrixBoldFont(getActivity(), viewCartBtn);
displayPrice = (TextView) rootview.findViewById(R.id.textView_totalprice_cart);
noOfItemsInCart = (TextView) rootview.findViewById(R.id.cart_items_quantity);
viewCartBtn.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), ViewCartActivity.class);
intent.putExtra(AppConstants.SUBTOTAL, Integer.parseInt(displayPrice.getText().toString()));
startActivity(intent);
}
});
LinearLayout itemsInCartLinearLayout = (LinearLayout) rootview.findViewById(R.id.ll_items_in_cart);
itemsInCartLinearLayout.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intent = new Intent(getActivity(), ViewCartActivity.class);
intent.putExtra(AppConstants.SUBTOTAL, Integer.parseInt(displayPrice.getText().toString()));
startActivity(intent);
}
});
}

This is "MenuDetailFragment" class
public class MenuDetailFragment extends Fragment {
View rootview;
private ListView listView;
private ArrayList<MenuHeadingDetailsModel> menuheadingDetailList;
private Communicate comm;
LinkedHashMap<String, ViewCartDetailsModel> viewCartDetailsModelMap = new LinkedHashMap<>();
ViewCartDetailsModel viewCartDetailsModel;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
// Inflate the layout for this fragment
rootview = inflater.inflate(R.layout.menu_list, container, false);
InitializeViews();
return rootview;
}
public void InitializeViews() {
listView = (ListView) rootview.findViewById(R.id.menu_items_list);
Bundle bundle = getArguments();
menuheadingDetailList = bundle.getParcelableArrayList(AppConstants.MENU_KEY);
listView.setAdapter(new MenuAdapter(getActivity(), menuheadingDetailList));[enter image description here][1]

这是＆＃34; MenuPagerAdapter＆＃34;类

public class MenuPagerAdapter extends FragmentStatePagerAdapter {
List<MenuModel> menu;
public MenuPagerAdapter(FragmentManager fm, List<MenuModel> menuList) {
super(fm);
this.menu = menuList;
}
@Override
public CharSequence getPageTitle(int position) {
return menu.get(position).getHeading().toString();
}
private List<MenuHeadingDetailsModel> getMenuHeadingDetails(int pos) {
return this.menu.get(pos).getMenuHeadingDetailList();
}
@Override
public Fragment getItem(int position) {
Fragment fragment = new MenuDetailFragment();
Bundle bundle = new Bundle();
bundle.putParcelableArrayList(AppConstants.MENU_KEY, (ArrayList<? extends Parcelable>) getMenuHeadingDetails(position));
fragment.setArguments(bundle);
return fragment;
}
@Override
public int getCount() {
return menu.size();
}
@Override
public void unregisterDataSetObserver(DataSetObserver observer) {
if (observer == null) {
super.unregisterDataSetObserver(observer);
}
}
@Override
public void destroyItem (ViewGroup container, int position, Object object)
{
Log.e("destroyitem","called");
}
}
class MenuAdapter extends BaseAdapter {
//ViewHolder holder;
Context context;
List<MenuHeadingDetailsModel> myItems = new ArrayList<>();
Button buttonPlus, buttonMinus;
int totalAmount = 0;
int pagePosition;
public MenuAdapter(Context context, List<MenuHeadingDetailsModel> myItems) {
this.context = context;
this.myItems = myItems;
}
@Override
public int getCount() {
return myItems.size();
}
@Override
public Object getItem(int position) {
return myItems.get(position);
}
@Override
public long getItemId(int position) {
return 0;
}
@Override
public View getView(final int position, View convertView, ViewGroup parent) {
final ViewHolder viewHolder = new ViewHolder();
final LayoutInflater inflater = getActivity().getLayoutInflater();
convertView = inflater.inflate(R.layout.menu_list_item, null);
viewHolder.codeText = (TextView) convertView.findViewById(R.id.textView_code);
viewHolder.nameText = (TextView) convertView.findViewById(R.id.textView_name);
AppMethods.setGlametrixBoldFont(getActivity(), viewHolder.nameText);
viewHolder.descText = (TextView) convertView.findViewById(R.id.textView_desc);
viewHolder.rateText = (TextView) convertView.findViewById(R.id.textView_rate);
viewHolder.textViewNoOfItems = (TextView) convertView.findViewById(R.id.tv_no_of_items);
buttonMinus = (Button) convertView.findViewById(R.id.button_minus);
buttonPlus = (Button) convertView.findViewById(R.id.button_plus);
final MenuHeadingDetailsModel menu = myItems.get(position);
viewHolder.codeText.setText(menu.getCode());
viewHolder.nameText.setText(menu.getItemName());
viewHolder.descText.setText(menu.getDescription());
viewHolder.rateText.setText(menu.getRate());
viewHolder.textViewNoOfItems.setText("" + menu.getQuantity());
buttonPlus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MenuHeadingDetailsModel menuList = myItems.get(position);
menuList.setQuantity(menuList.getQuantity() + 1);
myItems.set(position, menuList);
int itemRate = Integer.parseInt(myItems.get(position).getRate());
int itemQuan = menuList.getQuantity();
String code = menuList.getCode();
String name = menuList.getItemName();
int totalAmountPerItem = itemQuan * itemRate;
viewCartDetailsModel = new ViewCartDetailsModel(code, name, itemQuan, itemRate);
viewCartDetailsModelMap.put(viewCartDetailsModel.getCode(), viewCartDetailsModel);
Log.e("hashmap", "size" + viewCartDetailsModelMap.size());
Gson gson = new Gson();
String hashMapToString = gson.toJson(viewCartDetailsModelMap);
AppPreferences.saveDataInSharedpreferences(getActivity(), AppConstants.VIEW_ITEMS_INT_CART_KEY, hashMapToString);
totalAmount += itemRate;
int amount = totalAmount;
onButtonPressedForAmount(amount);
notifyDataSetChanged();
int quan = 0;
TextView tv;
for (int i = 0; i < listView.getCount(); i++) {
View view = listView.getAdapter().getView(i, null, null);
tv = (TextView) view.findViewById(R.id.tv_no_of_items);
quan = quan + Integer.parseInt(tv.getText().toString());
}
onButtonClickedForQuantity(quan);
}
}
);
buttonMinus.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
MenuHeadingDetailsModel menuList = myItems.get(position);
if ((menuList.getQuantity() - 1) >= 0) {
menuList.setQuantity(menuList.getQuantity() - 1);
myItems.set(position, menuList);
int itemRate = Integer.parseInt(myItems.get(position).getRate());
int itemQuan = menuList.getQuantity();
String code = menuList.getCode();
String name = menuList.getItemName();
//int totalAmountPerItem = itemQuan * itemRate;
viewCartDetailsModel = new ViewCartDetailsModel(code, name, itemQuan, itemRate);
if (itemQuan == 0) {
viewCartDetailsModelMap.remove(code);
} else {
viewCartDetailsModelMap.put(viewCartDetailsModel.getCode(), viewCartDetailsModel);
}
Gson gson = new Gson();
String hashMapToString = gson.toJson(viewCartDetailsModelMap);
AppPreferences.saveDataInSharedpreferences(getActivity(), AppConstants.VIEW_ITEMS_INT_CART_KEY, hashMapToString);
if (totalAmount > 0) {
totalAmount -= itemRate;
Log.e("totalamount", "minus" + totalAmount);
int amount = totalAmount;
onButtonPressedForAmount(amount);
}
} else {
menuList.setQuantity(0);
myItems.set(position, menuList);
}
notifyDataSetChanged();
int quan = 0;
TextView tv;
for (int i = 0; i < listView.getCount(); i++) {
View view = listView.getAdapter().getView(i, null, null);
tv = (TextView) view.findViewById(R.id.tv_no_of_items);
quan = quan + Integer.parseInt(tv.getText().toString());
}
onButtonClickedForQuantity(quan);
}
}
);
return convertView;
}
public void onButtonPressedForAmount(int userData) {
if (comm != null) {
comm.sendAmount(userData);
}
}
public void onButtonClickedForQuantity(int quantity) {
if (comm != null) {
comm.sendQuantity(quantity);
}
}
class ViewHolder {
TextView nameText;
TextView codeText;
TextView descText;
TextView rateText;
TextView textViewNoOfItems;
}
 }
//For settings fonts to the alert diaolog for customization of items
//public void setGlametrixBoldFont(TextView textView) {
//Typeface typeface = Typeface.createFromAsset(getActivity().getAssets(), "fonts/GlametrixBold.otf");
//textView.setTypeface(typeface);
// }
@Override
public void onAttach(Activity activity) {
super.onAttach(activity);
try {
comm = (Communicate) activity;
} catch (Exception e) {
AppMethods.getStackTrace(e);
}
}
public interface Communicate {
public void sendAmount(int amount);
public void sendQuantity(int quantity);
}
//    public void getPosition(int Position) {
//
//        int pagePosition = Position;
//        Log.e("pos", " " + pagePosition);
//    }
}

1 个答案:

答案 0 :(得分：0)

您可以按照以下方式在视图寻呼机内获取当前片段

SampleFragment sampleFr = (SampleFragment) viewPager.getAdapter().instantiateItem(viewPager, 0);

现在，您可以使用该片段访问所需的任何数据。

第一次在视图寻呼机中添加片段的方式如下所示。

        BaseFragment frTimeLine = (BaseFragment) Fragment.instantiate(this, SampleFragment.class.getName());
        fragments.add(frTimeLine);
        BaseFragment frEarnTiqs = (BaseFragment) Fragment.instantiate(this, SampleFragment1.class.getName());
        fragments.add(frEarnTiqs);


        adapter = new ViewPagerAdapter(getSupportFragmentManager(), getResources(), fragments);
        viewPager.setAdapter(adapter);
        viewPager.setOffscreenPageLimit(3);
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