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リスト内のアイテムの価格を計算し、その値をsharedpreferenceに保存したいとします。各商品にはdoubleの形を取る価格があります。問題は、私の方法を使用するときに、リスト内の1つの項目だけを考慮し、その値を計算することです。私はNumberPickerを使って商品の数量を変更しています。ここでリサイクルビューのアイテム一覧のアイテムの合計価格を計算する
はRecyclerView上に表示される項目のリストを処理するための私のアダプタである：ここでは
public class CartAdapter extends RecyclerView.Adapter<CartAdapter.ViewHolder> {
private List<SingleItem> items;
private SessionManager sessionManager;
private Context context;
private int pos;
public CartAdapter() {
}
public CartAdapter(Context context, List<SingleItem> items) {
this.items = items;
this.context = context;
sessionManager = new SessionManager(context);
}
@Override
public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
View view = LayoutInflater.from(parent.getContext()).inflate(R.layout.cartitem, parent, false);
return new ViewHolder(view);
}
@Override
public void onBindViewHolder(final ViewHolder holder, final int position) {
final SingleItem singleItem = items.get(position);
holder.tv_title.setText(singleItem.getTitle());
holder.tv_price.setText("Ksh: " + singleItem.getPrice());
Picasso.with(context).load(singleItem.getUrl()).fit().into(holder.imgcart);
holder.numcart.setMinValue(1);
holder.numcart.setMaxValue(15);
holder.numcart.setWrapSelectorWheel(false);
int qty = holder.numcart.getValue();
getTotal(qty, singleItem.getPrice());
}
public double getTotal(int value, double amount){
double totalamount;
double amountall = amount;
int quantity = value;
totalamount = amountall * quantity;
sessionManager.grandtotal("Ksh: " + totalamount);
return totalamount;
}
@Override
public int getItemCount() {
return items.size();
}
public void removeItem(SingleItem item) {
sessionManager.removeitem(context,item);
items.remove(item);
notifyDataSetChanged();
}
public class ViewHolder extends RecyclerView.ViewHolder {
TextView tv_price;
TextView tv_title;
NumberPicker numcart;
ImageView imgcart;
public ViewHolder(View view) {
super(view);
tv_price = (TextView) view.findViewById(R.id.titlecart);
tv_title = (TextView) view.findViewById(R.id.pricecart);
numcart = (NumberPicker) view.findViewById(R.id.pickercart);
imgcart = (ImageView) view.findViewById(R.id.imgcart);
}
}
}
は私が断片上RecyclerViewを表示しています方法です：
public class Details extends Fragment {
private RecyclerView RecyclerDetails;
private TextView CartPrice;
private CheckBox CheckCart;
private List<SingleItem> list;
private CartAdapter adapter;
private boolean add = false;
private Paint p = new Paint();
private SessionManager sessionManager;
private int pos;
public Details() {
// Required empty public constructor
}
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,Bundle savedInstanceState) {
// Inflate the layout for this fragment
View view = inflater.inflate(R.layout.fragment_details, container, false);
RecyclerDetails = (RecyclerView) view.findViewById(R.id.recyclercart);
CartPrice = (TextView) view.findViewById(R.id.tvcarttotal);
CheckCart = (CheckBox) view.findViewById(R.id.chkcart);
sessionManager = new SessionManager(getContext());
Toasty.info(getContext(),"Swipe to go to Next", Toast.LENGTH_SHORT,true).show();
RecyclerDetails.setHasFixedSize(true);
RecyclerView.LayoutManager layoutManager = new LinearLayoutManager(getContext());
RecyclerDetails.setLayoutManager(layoutManager);
list = sessionManager.getItems(getContext());
HashMap<String,String> map = sessionManager.itemstostring();
String data = map.get(SessionManager.KEY_ITEMS);
Log.i(Constants.TAG,data);
HashMap<String,String> tot = sessionManager.getgrandtotal();
String total = tot.get(SessionManager.KEY_TOTAL);
CartPrice.setText(total);
CheckCart.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
if (((CheckBox) v).isChecked()){
sessionManager.saveditems("true");
} else {
sessionManager.saveditems("false");
}
}
});
RecyclerDetails.addOnItemTouchListener(new RecyclerItemClickListener(getContext(), new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
}
}));
if(list != null){
adapter = new CartAdapter(getContext(),list);
RecyclerDetails.setAdapter(adapter);
}
initswipe();
return view;
}
private void initswipe() {
ItemTouchHelper.SimpleCallback simpleItemTouchCallback = new ItemTouchHelper.SimpleCallback(0, ItemTouchHelper.RIGHT) {
@Override
public boolean onMove(RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, RecyclerView.ViewHolder target) {
return false;
}
@Override
public void onSwiped(RecyclerView.ViewHolder viewHolder, int direction) {
int position = viewHolder.getAdapterPosition();
if (direction == ItemTouchHelper.RIGHT) {
adapter.removeItem(list.get(position));
sessionManager.saveitems(getContext(),list);
}
}
@Override
public void onChildDraw(Canvas c, RecyclerView recyclerView, RecyclerView.ViewHolder viewHolder, float dX, float dY, int actionState, boolean isCurrentlyActive) {
Bitmap icon;
if(actionState == ItemTouchHelper.ACTION_STATE_SWIPE){
View itemView = viewHolder.itemView;
float height = (float) itemView.getBottom() - (float) itemView.getTop();
float width = height/3;
if(dX > 0){
p.setColor(Color.parseColor("#14a895"));
RectF background = new RectF((float) itemView.getLeft(), (float) itemView.getTop(), dX,(float) itemView.getBottom());
c.drawRect(background,p);
icon = BitmapFactory.decodeResource(getResources(), android.R.drawable.ic_menu_delete);
RectF icon_dest = new RectF((float) itemView.getLeft() + width ,(float) itemView.getTop() + width,(float) itemView.getLeft()+ 2*width,(float)itemView.getBottom() - width);
c.drawBitmap(icon,null,icon_dest,p);
} else {
p.setColor(Color.parseColor("#14a895"));
RectF background = new RectF((float) itemView.getRight() + dX, (float) itemView.getTop(),(float) itemView.getRight(), (float) itemView.getBottom());
c.drawRect(background,p);
icon = BitmapFactory.decodeResource(getResources(),android.R.drawable.ic_menu_delete);
RectF icon_dest = new RectF((float) itemView.getRight() - 2*width ,(float) itemView.getTop() + width,(float) itemView.getRight() - width,(float)itemView.getBottom() - width);
c.drawBitmap(icon,null,icon_dest,p);
}
}
super.onChildDraw(c, recyclerView, viewHolder, dX, dY, actionState, isCurrentlyActive);
}
};
ItemTouchHelper itemTouchHelper = new ItemTouchHelper(simpleItemTouchCallback);
itemTouchHelper.attachToRecyclerView(RecyclerDetails);
}
}
そして、最後に、リスト内のすべてのアイテムの合計の値を格納する関数を次に示します。
public void grandtotal (String total){
editor.putString(KEY_TOTAL,total);
editor.commit();
}
public HashMap<String, String> getgrandtotal(){
HashMap<String, String> tot = new HashMap<>();
tot.put(KEY_TOTAL,pref.getString(KEY_TOTAL,null));
return tot;
}
アイテムにRecyclerViewと表示されている部分に含まれていない機能はありますか？
ちょっとした変更が必要ですか？
単品での価格を計算しているだけなので、合計金額が表示されます。 forループを入れて、前の合計に現在の価格を追加してループ内の総価格を計算する –