Java 添加到在android中工作的购物车设计

我正在开发一款类似于电子商务的应用程序。用户可以将产品添加到购物车。
我在下面提到了两个数组列表

public ArrayList<Design> cartList = new ArrayList<Design>();
public ArrayList<Design> designList = new ArrayList<Design>(); 

Single_DesignAdapter.java

公共类单_指定适配器扩展了RecyclerView.Adapter{
公共阵列列表设计列表；
私人语境；
私人停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场停车场；
public ArrayList cartList=null；
公共单_指定适配器（上下文上下文、ArrayList设计列表）{
this.designList=设计列表；
this.context=上下文；
this.layoutInflater=layoutInflater.from（上下文）；
if（cartList！=null）{
字符串cart=getSharePref（上下文，“cart”）；
Design[]designs=new Gson（）.fromJson（购物车，Design[].class）；
cartList=（ArrayList）Arrays.asList（designs）；
}
}
@凌驾
public ViewHolder onCreateViewHolder（视图组父级，int-viewType）{
视图=布局更平坦。充气（R.layout.single_design，parent，false）；
返回新的ViewHolder（视图）；
}
@凌驾
公共无效onBindViewHolder（最终视图持有人，最终整型位置）{
最终设计=设计列表。获取（位置）；
holder.tvQuality.setText（design.qualityName）；
holder.tvDesign.setText（design.designName）；
holder.tvShade.setText（设计名称）；
如果（！design.discPercent.等于（“0”））{
holder.tvDisPer.setText（“-”+design.dispercent+“%”）；
holder.TVAMUNT.setPaintFlags（holder.TVAMUNT.getPaintFlags（）| Paint.STRIKE_至_TEXT_标志）；
int a=整数.parseInt（设计量）；
浮点数b=浮点数。解析浮点数（设计百分比）/100；
holder.tvAmount.setText（“₹ " + 设计（数量）；
int c=（int）（a*b）；
int d=a-c；
holder.tvdiscament.setText（“₹ “+d）；
毕加索.with（context）.load（design.image）.into（holder.ivDesign）；
}否则{
holder.tvAmount.setText（“₹ “+设计金额）；
毕加索.with（context）.load（design.image）.into（holder.ivDesign）；
支架.tvDisPer.setVisibility（视图.不可见）；
holder.tvDiscAmt.setVisibility（视图不可见）；
}
if（cartList！=null）{
用于（设计d：cartList）{
if（design.id==d.id）{
design.pcs=d.pcs；
}
}
}
如果（design.pcs！=0）{
holder.llAdd.setVisibility（视图已消失）；
holder.llPlusMinus.setVisibility（View.VISIBLE）；
holder.btpcscont.setText（Integer.toString（design.pcs））；
}
holder.btAdd.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
holder.llAdd.setVisibility（视图已消失）；
holder.llPlusMinus.setVisibility（View.VISIBLE）；
if（cartList！=null）{
if（cartList.contains（设计））{
cartList.删除（设计）；
设计参数：pcs=1；
cartList.add（设计）；
saveSharedRef（上下文，“cart”，new Gson（）.toJson（cartList））；
（（活动）上下文）.invalidateOptions菜单（）；
}否则{
设计参数：pcs=1；
cartList.add（设计）；
saveSharedRef（上下文，“cart”，new Gson（）.toJson（cartList））；
（（活动）上下文）.invalidateOptions菜单（）；
}
}否则{
cartList=newarraylist（Arrays.asList（design））；
cartList.删除（设计）；
设计参数：pcs=1；
cartList.add（设计）；
saveSharedRef（上下文，“cart”，new Gson（）.toJson（cartList））；
（（活动）上下文）.invalidateOptions菜单（）；
}
}
});
holder.btPlus.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
if（Integer.parseInt（holder.btpcscont.getText（）.toString（））>=1）{
int a=Integer.parseInt（holder.btpcscont.getText（）.toString（））；
a++；
holder.btpcscont.setText（Integer.toString（a））；
if（cartList！=null）{
if（cartList.contains（设计））{
cartList.删除（设计）；
design.pcs=a；
cartList.add（设计）；
saveSharedRef（上下文，“cart”，new Gson（）.toJson（cartList））；
（（活动）上下文）.invalidateOptions菜单（）；
}否则{
design.pcs=a；
cartList.add（设计）；
saveSharedRef（上下文，“cart”，new Gson（）.toJson（cartList））；
（（活动）上下文）.invalidateOptions菜单（）；
}
}
}
}
});
holder.btemission.setOnClickListener（新视图.OnClickListener（）{
@凌驾
公共void onClick（视图）{
if（Integer.parseInt（holder.btpcscont.getText（）.toString（））刚刚更改了以下构造函数代码，它开始工作

public Single_DesignAdapter(Context context, ArrayList<Design> designList) {
    this.designList = designList;
    this.context = context;
    this.layoutInflater = LayoutInflater.from(context);

    String cart = getSharePref(context, "cart");
    Design[] designs = new Gson().fromJson(cart, Design[].class);

    if (cartList != null) {
        cartList = new ArrayList<Design>(Arrays.asList(designs));
    } else {
        if (designs != null) {
            cartList = new ArrayList<Design>();
            for (Design d : designs) {
                cartList.add(d);
            }
        }
    }
}

public Single_DesignAdapter（上下文上下文，ArrayList设计列表）{
this.designList=设计列表；
this.context=上下文；
this.layoutInflater=layoutInflater.from（上下文）；
字符串cart=getSharePref（上下文，“cart”）；
Design[]designs=new Gson（）.fromJson（购物车，Design[].class）；
if（cartList！=null）{
cartList=newarraylist（Arrays.asList（designs））；
}否则{
如果（设计！=null）{
cartList=newarraylist（）；
设计（d）
public class Single_DesignAdapter extends RecyclerView.Adapter<Single_DesignAdapter.ViewHolder> {

    public ArrayList<Design> designList;
    private Context context;
    private LayoutInflater layoutInflater;
    public ArrayList<Design> cartList = null;

    public Single_DesignAdapter(Context context, ArrayList<Design> designList) {
        this.designList = designList;
        this.context = context;
        this.layoutInflater = LayoutInflater.from(context);

        if (cartList != null) {
            String cart = getSharePref(context, "cart");
            Design[] designs = new Gson().fromJson(cart, Design[].class);
            cartList = (ArrayList<Design>) Arrays.asList(designs);
        }
    }

    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = layoutInflater.inflate(R.layout.single_design, parent, false);
        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(final ViewHolder holder, final int position) {

        final Design design = designList.get(position);
        holder.tvQuality.setText(design.qualityName);
        holder.tvDesign.setText(design.designName);
        holder.tvShade.setText(design.name);

        if (!design.discPercent.equals("0")) {
            holder.tvDisPer.setText("-"+design.discPercent+"%");
            holder.tvAmount.setPaintFlags(holder.tvAmount.getPaintFlags() | Paint.STRIKE_THRU_TEXT_FLAG);
            int a = Integer.parseInt(design.amount);
            float b = Float.parseFloat(design.discPercent) / 100;
            holder.tvAmount.setText("₹ " + design.amount);
            int c = (int) (a * b);
            int d = a-c;
            holder.tvDiscAmt.setText("₹ " +d);
            Picasso.with(context).load(design.image).into(holder.ivDesign);
        } else {
            holder.tvAmount.setText("₹ " + design.amount);
            Picasso.with(context).load(design.image).into(holder.ivDesign);
            holder.tvDisPer.setVisibility(View.INVISIBLE);
            holder.tvDiscAmt.setVisibility(View.INVISIBLE);
        }

        if (cartList != null) {
            for (Design d : cartList) {
                if (design.id == d.id) {
                    design.pcs = d.pcs;
                }
            }
        }

        if (design.pcs != 0) {
            holder.llAdd.setVisibility(View.GONE);
            holder.llPlusMinus.setVisibility(View.VISIBLE);
            holder.btPcsCount.setText(Integer.toString(design.pcs));
        }

        holder.btAdd.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                holder.llAdd.setVisibility(View.GONE);
                holder.llPlusMinus.setVisibility(View.VISIBLE);
                if (cartList != null) {
                    if (cartList.contains(design)) {
                        cartList.remove(design);
                        design.pcs = 1;
                        cartList.add(design);
                        saveSharedPref(context, "cart", new Gson().toJson(cartList));
                        ((Activity) context).invalidateOptionsMenu();
                    } else {
                        design.pcs = 1;
                        cartList.add(design);
                        saveSharedPref(context, "cart", new Gson().toJson(cartList));
                        ((Activity) context).invalidateOptionsMenu();
                    }
                } else {
                    cartList = new ArrayList<Design>(Arrays.asList(design));
                    cartList.remove(design);
                    design.pcs = 1;
                    cartList.add(design);
                    saveSharedPref(context, "cart", new Gson().toJson(cartList));
                    ((Activity) context).invalidateOptionsMenu();
                }
            }
        });

        holder.btPlus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (Integer.parseInt(holder.btPcsCount.getText().toString()) >= 1) {
                    int a = Integer.parseInt(holder.btPcsCount.getText().toString());
                    a++;
                    holder.btPcsCount.setText(Integer.toString(a));
                    if (cartList != null) {
                        if (cartList.contains(design)) {
                            cartList.remove(design);
                            design.pcs = a;
                            cartList.add(design);
                            saveSharedPref(context, "cart", new Gson().toJson(cartList));
                            ((Activity) context).invalidateOptionsMenu();
                        } else {
                            design.pcs = a;
                            cartList.add(design);
                            saveSharedPref(context, "cart", new Gson().toJson(cartList));
                            ((Activity) context).invalidateOptionsMenu();
                        }
                    }
                }
            }
        });

        holder.btMinus.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View view) {
                if (Integer.parseInt(holder.btPcsCount.getText().toString()) <= 1) {
                    holder.llAdd.setVisibility(View.VISIBLE);
                    holder.llPlusMinus.setVisibility(View.GONE);
                        cartList.remove(design);
                        saveSharedPref(context, "cart", new Gson().toJson(cartList));
                        ((Activity) context).invalidateOptionsMenu();
                } else {
                    int a = Integer.parseInt(holder.btPcsCount.getText().toString());
                    a--;
                    holder.btPcsCount.setText(Integer.toString(a));
                        cartList.remove(design);
                        design.pcs = a;
                        cartList.add(design);
                        saveSharedPref(context, "cart", new Gson().toJson(cartList));
                        ((Activity) context).invalidateOptionsMenu();
                }
            }
        });
    }

    @Override
    public int getItemCount() {
        return designList.size();
    }

    public class ViewHolder extends RecyclerView.ViewHolder {

        public LinearLayout llPer, llAdd, llPlusMinus;
        public Button btPlus, btMinus, btPcsCount, btAdd;
        public ImageView ivDesign;
        public TextView tvDesign, tvQuality, tvShade, tvAmount, tvDiscAmt, tvDisPer;

        public ViewHolder(View itemView) {
            super(itemView);

            llAdd = (LinearLayout) itemView.findViewById(R.id.llAdd);
            llPlusMinus = (LinearLayout) itemView.findViewById(R.id.llPlusMinus);
            btPlus = (Button) itemView.findViewById(R.id.btPlus);
            btAdd = (Button) itemView.findViewById(R.id.btAdd);
            //other findViewByIds
        }
    }
}

public class MainActivity extends AppCompatActivity {

    private RecyclerView recyclerView;
    private Single_DesignAdapter adapter;
    private ArrayList<Design> designList;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        recyclerView = (RecyclerView) findViewById(R.id.recycler_view);
    }

    @Override
    protected void onResume() {
        super.onResume();
        designList = new ArrayList<Design>();
        designList = list();

        /*if (cartList != null) {
            String cart = getSharePref(MainActivity.this, "cart");
            Design[] designs = new Gson().fromJson(cart, Design[].class);
            cartList = (ArrayList<Design>) Arrays.asList(designs);
        }*/

        recyclerView.setLayoutManager(new LinearLayoutManager(MainActivity.this));
        recyclerView.setHasFixedSize(true);
        adapter = new Single_DesignAdapter(MainActivity.this, designList);
        recyclerView.setAdapter(adapter);

        invalidateOptionsMenu();
    }

    public ArrayList<Design> list() {
        ArrayList<Design> arrayList = new ArrayList<Design>();

        Design design = new Design();
        design.id = 1;
        design.name = "Black";
        design.image = "http://linksolutions.in/Demo/images/1.jpg";
        design.designName = "11001";
        design.qualityName = "Cotton";
        design.amount = "1000";
        design.discPercent = "5";

        Design design2 = new Design();
        design2.id = 2;
        design2.name = "Green";
        design2.image = "http://linksolutions.in/Demo/images/2.jpg";
        design2.designName = "11001";
        design2.qualityName = "Cotton";
        design2.amount = "900";
        design2.discPercent = "9";

        Design design3 = new Design();
        design3.id = 3;
        design3.name = "Green";
        design3.image = "http://linksolutions.in/Demo/images/2.jpg";
        design3.designName = "11002";
        design3.qualityName = "Satin";
        design3.amount = "1200";
        design3.discPercent = "12";

        arrayList.add(design);
        arrayList.add(design2);
        arrayList.add(design3);

        return arrayList;
    }

    public static void setBadgeCount(Context context, LayerDrawable icon, int count) {

        BadgeDrawable badge;

        // Reuse drawable if possible
        Drawable reuse = icon.findDrawableByLayerId(R.id.ic_badge);
        if (reuse != null && reuse instanceof BadgeDrawable) {
            badge = (BadgeDrawable) reuse;
        } else {
            badge = new BadgeDrawable(context);
        }

        badge.setCount(count);
        icon.mutate();
        icon.setDrawableByLayerId(R.id.ic_badge, badge);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {

        getMenuInflater().inflate(R.menu.cart_menu, menu);
        MenuItem itemCart = menu.findItem(R.id.menu_cart);
        LayerDrawable icon = (LayerDrawable) itemCart.getIcon();
        String list = getSharePref(MainActivity.this, "cart");
        if (list != null) {
            Design[] designs = new Gson().fromJson(list, Design[].class);
            int count = designs.length;
            setBadgeCount(MainActivity.this, icon, count);
        }
        return super.onCreateOptionsMenu(menu);
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {

            case R.id.menu_cart:
                Intent intent = new Intent(MainActivity.this, CheckOutActivity.class);
                startActivity(intent);
                return false;
            default:
                break;
        }
        return false;

    }
}

public Single_DesignAdapter(Context context, ArrayList<Design> designList) {
    this.designList = designList;
    this.context = context;
    this.layoutInflater = LayoutInflater.from(context);

    String cart = getSharePref(context, "cart");
    Design[] designs = new Gson().fromJson(cart, Design[].class);

    if (cartList != null) {
        cartList = new ArrayList<Design>(Arrays.asList(designs));
    } else {
        if (designs != null) {
            cartList = new ArrayList<Design>();
            for (Design d : designs) {
                cartList.add(d);
            }
        }
    }
}