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);
}
}
}