我有一个RecyclerView，并在其中设置了一些TextView的文本。当我向下滚动或我的Fragment进入onPause状态时，我的数据丢失了。我该怎么办？
import static com.test.mohammaddvi.snappfood.Adapter.SectionListDataAdapter.decodeSampledBitmapFromResource;
public class RecyclerViewMenuFragmentAdapter extends RecyclerView.Adapter<RecyclerViewMenuFragmentAdapter.SingleItemInMenuFragment> {
private ArrayList<Food> foodList;
private Context mContext;
public RecyclerViewMenuFragmentAdapter(ArrayList<Food> foodList, Context mContext) {
this.foodList = foodList;
this.mContext = mContext;
}
@NonNull
@Override
public RecyclerViewMenuFragmentAdapter.SingleItemInMenuFragment onCreateViewHolder(ViewGroup parent, int viewType) {
View v = LayoutInflater.from(parent.getContext()).inflate(R.layout.foodlist, null);
return new RecyclerViewMenuFragmentAdapter.SingleItemInMenuFragment(v);
}
@Override
public void onBindViewHolder(final RecyclerViewMenuFragmentAdapter.SingleItemInMenuFragment holder, int position) {
Food food = foodList.get(position);
holder.foodName.setText(food.getName());
holder.foodDetails.setText(food.getDetails());
holder.foodPrice.setText(food.getPrice() + " تومان ");
holder.foodOrderNumber.setVisibility(View.INVISIBLE);
holder.foodMinusButton.setVisibility(View.INVISIBLE);
holder.foodOrderNumber.setText(0 + "");
holder.foodImage.setImageBitmap(decodeSampledBitmapFromResource(mContext.getResources(), mContext.getResources().getIdentifier(food.getImage(),
"drawable", mContext.getPackageName()), 50, 50));
handleClick(holder, position);
}
private void handleClick(final SingleItemInMenuFragment holder, final int position) {
holder.foodPlusButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int orderNumber = Integer.parseInt(holder.foodOrderNumber.getText().toString());
holder.foodOrderNumber.setText(orderNumber + 1 + "");
holder.foodOrderNumber.setVisibility(View.VISIBLE);
holder.foodMinusButton.setVisibility(View.VISIBLE);
}
});
holder.foodMinusButton.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
int orderNumber = Integer.parseInt(holder.foodOrderNumber.getText().toString());
if (orderNumber > 1) {
holder.foodOrderNumber.setText(orderNumber - 1 + "");
holder.foodOrderNumber.setVisibility(View.VISIBLE);
}
if (orderNumber == 1) {
holder.foodOrderNumber.setText(orderNumber - 1 + "");
holder.foodOrderNumber.setVisibility(View.INVISIBLE);
holder.foodMinusButton.setVisibility(View.INVISIBLE);
}
}
});
}
@Override
public int getItemCount() {
return (null != foodList ? foodList.size() : 0);
}
public class SingleItemInMenuFragment extends RecyclerView.ViewHolder {
TextView foodName;
TextView foodPrice;
Button foodPlusButton;
Button foodMinusButton;
TextView foodOrderNumber;
ImageView foodImage;
TextView foodDetails;
SingleItemInMenuFragment(View itemView) {
super(itemView);
this.foodName = itemView.findViewById(R.id.foodName);
this.foodImage = itemView.findViewById(R.id.imageFood);
this.foodPrice = itemView.findViewById(R.id.foodPrice);
this.foodDetails = itemView.findViewById(R.id.foodDetails);
this.foodPlusButton = itemView.findViewById(R.id.plusbutton);
this.foodMinusButton = itemView.findViewById(R.id.minusbutton);
this.foodOrderNumber = itemView.findViewById(R.id.ordernumber);
}
}
这是我在RecyclerView中使用的片段：
...
public class MenuFragment extends Fragment{
private static final String TAG = "menufragment";
ArrayList<Food> allfoods = new ArrayList<>();
RecyclerView recyclerview;
private static Bundle bundle;
private final String KEY_RECYCLER_STATE= "recycler_state";
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
return inflater.inflate(R.layout.menufragment, container, false);
}
@Override
public void onStart() {
super.onStart();
String jsonFilePath = "foods.json";
recyclerview = getActivity().findViewById(R.id.lstitems);
RecyclerViewMenuFragmentAdapter adapter = new RecyclerViewMenuFragmentAdapter(allfoods, getContext());
recyclerview.setLayoutManager(new LinearLayoutManager(getContext(), LinearLayoutManager.VERTICAL, false));
recyclerview.setHasFixedSize(true);
recyclerview.setAdapter(adapter);
parsJson(jsonFilePath);
}
//this method is for read a local json and return a string
public String readLocalJson(String jsonFile) {
String json;
try {
InputStream is = getActivity().getAssets().open(jsonFile);
int size = is.available();
byte[] buffer = new byte[size];
is.read(buffer);
is.close();
json = new String(buffer, "UTF-8");
} catch (IOException e) {
e.printStackTrace();
return null;
}
return json;
}
public void parsJson(String jsonFilePath) {
try {
JSONObject obj = new JSONObject(readLocalJson(jsonFilePath));
JSONArray jsonArray = obj.getJSONArray("results");
for (int i = 0; i < jsonArray.length(); i++) {
JSONObject jsonObject = jsonArray.getJSONObject(i);
String image = jsonObject.getString("image");
JSONArray jsonArrayFoot = jsonObject.getJSONArray("foots");
for (int j = 0; j < jsonArrayFoot.length(); j++) {
JSONObject jsonObjectFoot = jsonArrayFoot.getJSONObject(j);
String foodName = jsonObjectFoot.getString("name");
String fooddetails = jsonObjectFoot.getString("fooddetails");
String price = jsonObjectFoot.getString("price");
allfoods.add(new Food(foodName, price, fooddetails, image));
}
}
} catch (JSONException e) {
e.printStackTrace();
}
}