购物车模板

  这个购物车的功能：

有加减器，全选反选CheckBox，价格的监听。用的是死数据，如果要求获得网络数据的话，

可以把数据改一下。

这里的数据展示用了RecyclerView,所以，需要导一个RecyclerView的依赖。这个自己导就不打了

代码如下：

先弄好加减器

布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"    android:layout_width="match_parent"    android:layout_height="match_parent">    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:text="-"        android:background="#fff"        android:id="@+id/jian"        />    <EditText        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:inputType="number"        android:text="1"        android:id="@+id/num"/>    <Button        android:layout_width="wrap_content"        android:layout_height="wrap_content"        android:background="#fff"        android:text="+"        android:id="@+id/jia"/></LinearLayout>

CustomView

import android.content.Context;import android.support.annotation.Nullable;import android.text.Editable;import android.text.TextWatcher;import android.util.AttributeSet;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.widget.Button;import android.widget.EditText;import android.widget.LinearLayout;import android.widget.Toast;/** * Created by czx on 2017/10/23. */public class CustomView extends LinearLayout{    public CustomView(Context context) {        super(context);    }    public CustomView(final Context context, @Nullable AttributeSet attrs) {        super(context, attrs);        View view = LayoutInflater.from(context).inflate(R.layout.custom_layout,null);        addView(view);        Button jian = (Button) view.findViewById(R.id.jian);        Button jia = (Button) view.findViewById(R.id.jia);        final EditText num = (EditText) view.findViewById(R.id.num);        //减号        jian.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                String result = num.getText().toString().trim();                int integerResult = Integer.valueOf(result);                //给做个限制                if(integerResult > 1){                    integerResult = integerResult - 1;                    num.setText(integerResult + "");                }else{                    Toast.makeText(context, "最小值为1", Toast.LENGTH_SHORT).show();                }                if(listener != null){                    listener.onChange(integerResult);                }            }        });        //加号        jia.setOnClickListener(new OnClickListener() {            @Override            public void onClick(View v) {                String result = num.getText().toString().trim();                int integerResult = Integer.valueOf(result);                if(integerResult < 10000){                    integerResult = integerResult + 1;                    num.setText(integerResult +"");                }else{                    Toast.makeText(context, "已经超出最大值", Toast.LENGTH_SHORT).show();                }                if(listener != null ){                    listener.onChange(integerResult);                }            }        });        num.addTextChangedListener(new TextWatcher() {            @Override            public void beforeTextChanged(CharSequence s, int start, int count, int after) {                Log.i("beforeTextChanged",s+"-----"+start+"-------"+count+"-----"+after);//                if(start < 0){//                    Toast.makeText(context, "000000000000000", Toast.LENGTH_SHORT).show();//                    s = "1";//                }else if(start > 4){//                    s = "10000";//                    Toast.makeText(context, "111111111", Toast.LENGTH_SHORT).show();//                }            }            @Override            public void onTextChanged(CharSequence s, int start, int before, int count) {                Log.i("onTextChanged",s+"-----"+start+"-------"+before+"-----"+count);            }            @Override            public void afterTextChanged(Editable s) {                if(listener != null ){                    listener.onChange(Long.valueOf(s.toString()));                }            }        });    }    public CustomView(Context context, @Nullable AttributeSet attrs, int defStyleAttr) {        super(context, attrs, defStyleAttr);    }    public ChangeListener listener;    public void setListener(ChangeListener listener){        this.listener = listener;    }    interface ChangeListener{        public void onChange(long count);    }}

写一个Bean

public class UserBean {    private String name;    private boolean b = false;    private float price;    private long count;    public UserBean(String name, boolean b, float price, long count) {        this.name = name;        this.b = b;        this.price = price;        this.count = count;    }    public String getName() {        return name;    }    public void setName(String name) {        this.name = name;    }    public boolean isB() {        return b;    }    public void setB(boolean b) {        this.b = b;    }    public float getPrice() {        return price;    }    public void setPrice(float price) {        this.price = price;    }    public long getCount() {        return count;    }    public void setCount(long count) {        this.count = count;    }}

然后是主界面的布局

<?xml version="1.0" encoding="utf-8"?><LinearLayout    xmlns:android="http://schemas.android.com/apk/res/android"    xmlns:app="http://schemas.android.com/apk/res-auto"    android:orientation="vertical"    xmlns:tools="http://schemas.android.com/tools" android:layout_width="match_parent"    android:layout_height="match_parent" >    <android.support.v7.widget.RecyclerView        android:layout_width="match_parent"        android:layout_height="0dp"        android:layout_weight="1"        android:id="@+id/recyclerview">    </android.support.v7.widget.RecyclerView>    <LinearLayout        android:layout_width="match_parent"        android:layout_height="50dp"        android:orientation="horizontal">        <CheckBox            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:layout_gravity="center"            android:id="@+id/ck_all"/>        <TextView            android:layout_width="wrap_content"            android:layout_height="match_parent"            android:text="全选"            android:textSize="20sp"            android:gravity="center"            />        <TextView            android:layout_width="0dp"            android:layout_weight="1"            android:layout_height="match_parent"            android:text="合计:"            android:layout_marginLeft="10dp"            android:textSize="20sp"            android:gravity="center_vertical"            android:id="@+id/all_price"            />        <Button            android:layout_width="wrap_content"            android:layout_height="wrap_content"            android:text="确认订单"            android:id="@+id/buy"/>    </LinearLayout></LinearLayout>

主界面代码

import android.os.Bundle;import android.support.v7.app.AppCompatActivity;import android.support.v7.widget.LinearLayoutManager;import android.support.v7.widget.RecyclerView;import android.view.View;import android.widget.Button;import android.widget.CheckBox;import android.widget.TextView;import java.util.ArrayList;import java.util.List;public class MainActivity extends AppCompatActivity {    private TextView all_price;    private CheckBox checkBox;    @Override    protected void onCreate(Bundle savedInstanceState) {        super.onCreate(savedInstanceState);        setContentView(R.layout.activity_main);        Button buy = (Button) findViewById(R.id.buy);        checkBox = (CheckBox) findViewById(R.id.ck_all);        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.recyclerview);        all_price = (TextView) findViewById(R.id.all_price);        LinearLayoutManager manager = new LinearLayoutManager(this);        recyclerView.setLayoutManager(manager);        //添加死数据        final List<UserBean> list = new ArrayList<>();        for (int i = 0; i < 5; i++) {            list.add(new UserBean("商品" + i, false, 100, 1));        }        final RvAdapter adapter = new RvAdapter(this, list);        recyclerView.setAdapter(adapter);        adapter.setCheckListener(new RvAdapter.CheckListener() {            @Override            public void check(boolean check, int position) {                //监听全选                boolean all_check = true;                //价格                float price = 0;                for (int i = 0; i < list.size(); i++) {                    if (list.get(i).isB()) {                        price += list.get(i).getPrice() * list.get(i).getCount();                    }                }                all_price.setText(price + "元");                for (int i = 0; i < list.size(); i++) {                    if (!list.get(i).isB()) {                        all_check = false;                        break;                    }                }                if (all_check) {                    checkBox.setChecked(true);                } else {                    checkBox.setChecked(false);                }            }        });        //全选和反选        checkBox.setOnClickListener(new View.OnClickListener() {            @Override            public void onClick(View v) {                boolean check = checkBox.isChecked();                float price = 0;                for (int i = 0; i < list.size(); i++) {                    list.get(i).setB(check);                    if (list.get(i).isB()) {                        price += list.get(i).getPrice() * list.get(i).getCount();                    }                }                adapter.notifyDataSetChanged();                all_price.setText(price + "元");            }        });    }}

RecylerView的适配器

import android.content.Context;import android.support.v7.widget.RecyclerView;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.CheckBox;import android.widget.TextView;import java.util.List;/** * Created by czx on 2017/10/22. */public class RvAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder>{    private Context context;    private List<UserBean> list;    public RvAdapter(Context context, List<UserBean> list) {        this.context = context;        this.list = list;    }    @Override    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {        View view = LayoutInflater.from(context).inflate(R.layout.item_layout,parent,false);        ViewHolder holder = new ViewHolder(view);        return holder;    }    @Override    public void onBindViewHolder(RecyclerView.ViewHolder holder, final int position) {        if(holder instanceof ViewHolder){            ViewHolder viewHolder = (ViewHolder)holder;            if(list.get(position).isB()){                viewHolder.item_ck.setChecked(true);            }else{                viewHolder.item_ck.setChecked(false);            }            viewHolder.item_name.setText(list.get(position).getPrice()+"");            viewHolder.item_ck.setOnClickListener(new View.OnClickListener() {                @Override                public void onClick(View v) {                    boolean isChecked = list.get(position).isB();                    list.get(position).setB(!isChecked);                    notifyDataSetChanged();                    if(listener != null){                        listener.check(!isChecked,position);                    }                }            });//            viewHolder.item_ck.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {//                @Override//                public void onCheckedChanged(CompoundButton buttonView, boolean isChecked) {////                }//            });            //监听Edtext            viewHolder.item_custom.setListener(new CustomView.ChangeListener() {                @Override                public void onChange(long count) {                    list.get(position).setCount(count);                    notifyDataSetChanged();                    if(listener != null){                        listener.check(list.get(position).isB(),position);                    }                }            });        }    }    @Override    public int getItemCount() {        return list.size();    }    //为check写一个接口    public CheckListener listener;    public void setCheckListener(CheckListener listener){        this.listener = listener;    }    interface CheckListener{        public void check(boolean check,int position);    }    class ViewHolder extends RecyclerView.ViewHolder{        private final CustomView item_custom;        private final TextView item_name;        private final CheckBox item_ck;        public ViewHolder(View itemView) {            super(itemView);            item_custom = (CustomView) itemView.findViewById(R.id.item_custom);            item_name = (TextView) itemView.findViewById(R.id.item_name);            item_ck = (CheckBox) itemView.findViewById(R.id.item_ck);        }    }}