20.购物车商品价格的总和（里面有一些功能没有实现，创建textview布局对象，然后for()遍历数据求和）

效果图：

在CartFragment中创建textview的对象，然后在CartAdapter适配器中的构造函数，实现textview的赋值，使用for遍历

代码：

CartFragment.class

package zuo.com.ui.fragment;

import android.content.Context;
import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;

import java.util.ArrayList;
import java.util.List;

import zuo.com.ui.HomeActivity;
import zuo.com.ui.MainActivity;
import zuo.com.ui.R;
import zuo.com.ui.adapter.CartAdapter;
import zuo.com.ui.adapter.HotGoodsAdapter;
import zuo.com.ui.bean.ShoppingCart;
import zuo.com.ui.util.CartProvider;

/**
 * Created by Administrator on 2016/10/6.
 */
public class CartFragment extends Fragment {
    private LayoutInflater layoutInflater;
    private CartProvider cartProvider;
    private CartAdapter cartAdapter;
    private RecyclerView recyclerView;
    private TextView textView;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        layoutInflater=LayoutInflater.from(getContext());
        cartProvider=new CartProvider(getContext());
        View view=layoutInflater.inflate(R.layout.fragment_cart,container,false);
        recyclerView= (RecyclerView) view.findViewById(R.id.recycler_view);
        textView= (TextView) view.findViewById(R.id.txt_total);
        showData();
        return view;
    }
    //初始化数据
    private void showData(){

        List<ShoppingCart> carts=HotGoodsAdapter.hashMap.get("123");
        if(carts!=null) {
            Log.d("cart", carts.get(0).getName());
            cartAdapter = new CartAdapter(carts,textView);
            recyclerView.setAdapter(cartAdapter);
            recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        }else{
            cartAdapter = new CartAdapter(carts,textView);
            recyclerView.setAdapter(cartAdapter);
            recyclerView.setLayoutManager(new LinearLayoutManager(getContext()));
        }
        }



}

CartAdapter:

package zuo.com.ui.adapter;

import android.net.Uri;
import android.support.v7.widget.RecyclerView;
import android.util.Log;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.CheckBox;
import android.widget.TextView;

import com.facebook.drawee.backends.pipeline.Fresco;
import com.facebook.drawee.backends.pipeline.PipelineDraweeController;
import com.facebook.drawee.view.SimpleDraweeView;
import com.facebook.imagepipeline.request.ImageRequest;
import com.facebook.imagepipeline.request.ImageRequestBuilder;

import java.util.List;

import zuo.com.ui.R;
import zuo.com.ui.bean.ShoppingCart;
import zuo.com.ui.number.NumberAddSubView;
import zuo.com.ui.util.CartProvider;

/**
 * Created by Administrator on 2016/10/17.
 */
public class CartAdapter extends RecyclerView.Adapter<CartAdapter.ViewHolder> {

    private LayoutInflater layoutInflater;
    private List<ShoppingCart> carts;
    private TextView textView;

    float sum=0;


    public CartAdapter(List<ShoppingCart> carts,TextView textView){
        this.carts=carts;
        this.textView=textView;
        textView.setText("￥"+total());
    }
    @Override
    public ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        layoutInflater=LayoutInflater.from(parent.getContext());
        View view=layoutInflater.inflate(R.layout.template_cart,parent,false);

        return new ViewHolder(view);
    }

    @Override
    public void onBindViewHolder(ViewHolder holder, int position) {
        holder.textView1.setText(carts.get(position).getName());
        Uri uri=Uri.parse(carts.get(position).getImgUrl());
        ImageRequest request = ImageRequestBuilder.newBuilderWithSource(uri)
                .setProgressiveRenderingEnabled(true)
                .build();
        PipelineDraweeController controller = (PipelineDraweeController) Fresco.newDraweeControllerBuilder()
                .setImageRequest(request)
                .build();
        holder.simpleDraweeView.setController(controller);
        Log.d("123",carts.get(position).getPrice());
        holder.textView2.setText("￥"+carts.get(position).getPrice());



    }
    private float total(){
        if(carts==null){
            return 0;
        }else{
            for(ShoppingCart s:carts){
                sum+=Float.parseFloat(s.getPrice());
            }
            return  sum;
        }
    }

    @Override
    public int getItemCount() {
        if(carts!=null) {
            return carts.size();
        }else{
            return 0;
        }
    }

    class ViewHolder extends RecyclerView.ViewHolder{
        private CheckBox checkBox;
        private SimpleDraweeView simpleDraweeView;
        private TextView textView1,textView2;
        private NumberAddSubView numberAddSubView1;


        public ViewHolder(View itemView) {
            super(itemView);
            checkBox= (CheckBox) itemView.findViewById(R.id.checkbox);
            checkBox.setClickable(true);
            simpleDraweeView= (SimpleDraweeView) itemView.findViewById(R.id.drawee_view);
            textView1= (TextView) itemView.findViewById(R.id.text_title);
            textView2= (TextView) itemView.findViewById(R.id.text_price);
            numberAddSubView1= (NumberAddSubView) itemView.findViewById(R.id.num_control);
            numberAddSubView1.setValue(1);
            numberAddSubView1.setClickable(true);
        }
    }
}