android 实现简单的一级购物车

**第一步导入依赖,如: compile 'com.squareup.okhttp3:okhttp:3.9.0' compile 'com.squareup.okhttp3:logging-interceptor:3.9.0' compile 'com.google.code.gson:gson:2.8.2' compile 'com.nostra13.universalimageloader:universal-image-loader:1.9.5' compile 'org.greenrobot:eventbus:3.1.1' compile 'com.android.support:recyclerview-v7:24.2.1' **别忘了 sync now******第二步添加权限,如:<uses-permission android:name="android.permission.INTERNET"></uses-permission>****第三步,上代码,最重要****net包(Api,HttpUtils,OnNetListener)****Api**public interface Api {    public static final String url = "http://result.eolinker.com/iYXEPGn4e9c6dafce6e5cdd23287d2bb136ee7e9194d3e9?uri=evaluation";}**HttpUtils**public class HttpUtils {    private static volatile HttpUtils httpUtils;    private final OkHttpClient client;    private HttpUtils() {        HttpLoggingInterceptor logging = new HttpLoggingInterceptor();        logging.setLevel(HttpLoggingInterceptor.Level.BODY);        client = new OkHttpClient.Builder()                .addInterceptor(logging)                .build();    }    public static HttpUtils getHttpUtils() {        if (httpUtils == null) {            synchronized (HttpUtils.class) {                if (httpUtils == null) {                    httpUtils = new HttpUtils();                }            }        }        return httpUtils;    }    public void doGet(String url, Callback callback) {        Request request = new Request.Builder().url(url).build();        client.newCall(request).enqueue(callback);    }}**OnNetListener**public interface OnNetListener<T> {    public void onSuccess(T t);    public void onFailure(Exception e);}**bean包(GoodsBean)****自己封装,注意封装时可以后加属性哦****adapter包(Myadapter)****Myadapter**public class Myadapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {    /*上下文*/    private Context context;    /*集合*/    private List<GoosBean.DataBean.DatasBean> list;    /*有参构造*/    public Myadapter(Context context, List<GoosBean.DataBean.DatasBean> list) {        this.context = context;        this.list = list;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {       /*1.加载item布局*/        View view = LayoutInflater.from(context).inflate(R.layout.item, parent, false);        return new MyViewHolder(view);    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {       /*3.把封装里的数据(datasBean.getType_name)放入优化器( myViewHolder.fx)*/        final GoosBean.DataBean.DatasBean datasBean = list.get(position);        final MyViewHolder myViewHolder = (MyViewHolder) holder;        myViewHolder.fx.setChecked(datasBean.isChecked());        myViewHolder.myphone.setText(datasBean.getType_name());        myViewHolder.myplace.setText(datasBean.getMsg());        myViewHolder.mytime.setText(datasBean.getAdd_time());        myViewHolder.myprice.setText(datasBean.getPrice() + "");        myViewHolder.add_num_del.setText(datasBean.getAdd_num_del() + "");/*要想实现反选效果，在适配器里，给反选设置点击事件，*/        myViewHolder.fx.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                /*反选打钩*/                datasBean.setChecked(myViewHolder.fx.isChecked());                /*结账时候写这两行，具体发送*/                PriceAndCountEvent compute = compute();                EventBus.getDefault().post(compute);                /*如果反选 都 打钩*/                if(myViewHolder.fx.isChecked()){                    /*走isAllCbSelected()方法，开始给遍历 判断 反选 状态*/                    if(isAllCbSelected()){                         /*changeAllCbState()方法，开始改变 全选 状态并发送*/                        changeAllCbState(true);                    }                }else{                    changeAllCbState(false);                }                notifyDataSetChanged();            }        });        /*直接,加+*/        myViewHolder.add.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                /*不一样*/                for (int i = 0; i < list.size(); i++) {                    GoosBean.DataBean.DatasBean datasBean = list.get(i);                }                int add_num_del = datasBean.getAdd_num_del();                add_num_del++;                datasBean.setAdd_num_del(add_num_del);                /*结账*/                    if(myViewHolder.fx.isChecked()){                        EventBus.getDefault().post(compute());                    }                notifyDataSetChanged();            }        });           /*直接,减-*/        myViewHolder.del.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                /*不一样*/                for (int i = 0; i < list.size(); i++) {                    GoosBean.DataBean.DatasBean datasBean = list.get(i);                }                int add_num_del = datasBean.getAdd_num_del();                if(add_num_del==1){                return;                }                add_num_del--;                datasBean.setAdd_num_del(add_num_del);                 /*结账*/                    if(myViewHolder.fx.isChecked()){                        EventBus.getDefault().post(compute());                    }                notifyDataSetChanged();            }        });        /*删除*/        myViewHolder.delete.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                list.remove(position);                EventBus.getDefault().post(compute());                notifyDataSetChanged();            }        });    }    @Override    public int getItemCount() {        return list.size();    }/*若全选，反选都选，allSelect()*/    public void allSelect(boolean flag) {        for (int i = 0; i < list.size(); i++) {            GoosBean.DataBean.DatasBean datasBean = list.get(i);            datasBean.setChecked(flag);        }        /*全选结账直接一句话*/        EventBus.getDefault().post(compute());        notifyDataSetChanged();    }    private boolean isAllCbSelected() {        for (int i = 0; i < list.size(); i++) {            GoosBean.DataBean.DatasBean datasBean = list.get(i);            if (!datasBean.isChecked()) {                return false;            }        }        return true;    }    /*改变全选状态，并发送*/    private void changeAllCbState(boolean flag) {        MessageEvent messageEvent = new MessageEvent();        messageEvent.setChecked(flag);        EventBus.getDefault().post(messageEvent);    }    /*写具体结账逻辑方法*/    private PriceAndCountEvent compute() {        int price = 0;        int count = 0;        for (int i = 0; i < list.size(); i++) {            GoosBean.DataBean.DatasBean datasBean = list.get(i);            if (datasBean.isChecked()) {                price += datasBean.getPrice() * datasBean.getAdd_num_del();                count += datasBean.getAdd_num_del();            }        }        PriceAndCountEvent priceAndCountEvent = new PriceAndCountEvent();        priceAndCountEvent.setPrice(price);        priceAndCountEvent.setCount(count);        return priceAndCountEvent;    }    /*2.找到布局里的ID*/    class MyViewHolder extends RecyclerView.ViewHolder {        private final CheckBox fx;        private final TextView myphone;        private final TextView myplace;        private final TextView mytime;        private final TextView myprice;        private final TextView add_num_del;        private final ImageView add;        private final ImageView del;        private final TextView delete;        public MyViewHolder(View itemView) {            super(itemView);            fx = (CheckBox) itemView.findViewById(R.id.fx);            myphone = (TextView) itemView.findViewById(R.id.myphone);            myplace = (TextView) itemView.findViewById(R.id.myplace);            myprice = (TextView) itemView.findViewById(R.id.myprice);            mytime = (TextView) itemView.findViewById(R.id.mytime);            add_num_del = (TextView) itemView.findViewById(R.id.add_num_del);            add = (ImageView) itemView.findViewById(R.id.add);            del = (ImageView) itemView.findViewById(R.id.del);            delete = (TextView) itemView.findViewById(R.id.delete);        }    }}**eventbusevent包(MessageEvent,PriceAndCountEvent)****MessageEvent**public class MessageEvent {    private boolean checked;    public boolean isChecked() {        return checked;    }    public void setChecked(boolean checked) {        this.checked = checked;    }}**PriceAndCountEvent**public class PriceAndCountEvent {    private int price;    private int count;    public int getPrice() {        return price;    }    public void setPrice(int price) {        this.price = price;    }    public int getCount() {        return count;    }    public void setCount(int count) {        this.count = count;    }}**model包(IMainModel,MainModel)****IMainModel**public interface IMainModel {    public void getGoods(OnNetListener<GoosBean> onNetListener);}*MainModel*public class MainModel implements IMainModel{    private Handler handler = new Handler(Looper.getMainLooper());    @Override    public void getGoods(final OnNetListener<GoosBean> onNetListener) {        HttpUtils.getHttpUtils().doGet(Api.url, new Callback() {            @Override            public void onFailure(Call call, IOException e) {            }            @Override            public void onResponse(Call call, Response response) throws IOException {            String string=response.body().string();                final GoosBean goosBean = new Gson().fromJson(string, GoosBean.class);                handler.post(new Runnable() {                    @Override                    public void run() {                        onNetListener.onSuccess(goosBean);                    }                });            }        });    }}**view(IMainActivity,MainActivity)****IMainActivity**public interface IMainActivity {    public void showList(List<GoosBean.DataBean.DatasBean> list);}**MainActivity**public class MainActivity extends AppCompatActivity implements IMainActivity{    private RecyclerView Rv;    private CheckBox qx;    private TextView tv_money;    private TextView tv_num;    private Myadapter myadapter;    private MainPresenter mainPresenter;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        /*注意！！！别忘啦,fx*/        EventBus.getDefault().register(this);        mainPresenter = new MainPresenter(this);        Rv = (RecyclerView) findViewById(R.id.Rv);        qx = (CheckBox) findViewById(R.id.qx);        tv_money = (TextView) findViewById(R.id.tv_money);        tv_num = (TextView) findViewById(R.id.tv_num);        Rv.setLayoutManager(new LinearLayoutManager(this));        mainPresenter.getGoods();/*给全选按钮设置点击事件,状态为ture*/        qx.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                /*具体勾选与否写在myadapter里*/                myadapter.allSelect(qx.isChecked());            }        });    }    @Override    public void showList(List<GoosBean.DataBean.DatasBean> list) {        myadapter = new Myadapter(this,list);        Rv.setAdapter(myadapter);    }   /* 接状态，@Subscribe*/    @Subscribe    public void onMessageEvent(MessageEvent event){        qx.setChecked(event.isChecked());    }    /*结账*/    @Subscribe    public void onMessageEvent(PriceAndCountEvent event) {        tv_num.setText("结算(" + event.getCount() + ")");        tv_money.setText(event.getPrice() + "");    }**presenter(MainPresenter )**public class MainPresenter {    private IMainModel iMainModel;    private IMainActivity iMainActivity;    public MainPresenter(IMainActivity iMainActivity) {        this.iMainActivity = iMainActivity;        iMainModel = new MainModel();    }    public void getGoods(){        iMainModel.getGoods(new OnNetListener<GoosBean>() {            @Override            public void onSuccess(GoosBean goosBean) {                List<GoosBean.DataBean.DatasBean> list = new ArrayList<GoosBean.DataBean.DatasBean>();                List<GoosBean.DataBean> data = goosBean.getData();                for (int i = 0; i < data.size(); i++) {                    List<GoosBean.DataBean.DatasBean> datas = data.get(i).getDatas();                    list.addAll(datas);                }                iMainActivity.showList(list);            }            @Override            public void onFailure(Exception e) {            }        });    }}