andriod——完美实现一级购物车

最新推荐文章于 2019-05-23 14:25:58 发布

qq_39714504

最新推荐文章于 2019-05-23 14:25:58 发布

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CC 4.0 BY-SA版权

文章标签：安卓开发一级购物车

本文链接：https://blog.youkuaiyun.com/qq_39714504/article/details/78585468

本文介绍了一个简单的购物车应用实现方案，使用RecyclerView展示商品列表，并通过自定义视图实现商品数量的增减。同时实现了全选功能及总价计算。

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//CarAdapter
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.Button;
import android.widget.CheckBox;
import android.widget.TextView;
import android.widget.Toast;


import java.util.List;

public class CarAdapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    private Context context;
    private List<CarBean> list;

    public CarAdapter(Context context, List<CarBean> list) {
        this.context = context;
        this.list = list;
    }

    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup parent, int viewType) {
        View view = LayoutInflater.from(context).inflate(R.layout.car_item,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).getName());
            viewHolder.item_price.setText("单价："+list.get(position).getPrice()+" ¥");
            viewHolder.item_des.setText("共计"+list.get(position).getCount()+"件，总价"+list.get(position).getCount()*100+"元");
            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);
                    }
                }
            });

            //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);
                    }
                }
            });

            viewHolder.del.setOnClickListener(new View.OnClickListener() {
                @Override
                public void onClick(View view) {
                    if (list.get(position).isB()){
                        Toast.makeText(context, "不能删除", Toast.LENGTH_SHORT).show();
                    }else {
                        list.remove(position);
                        notifyDataSetChanged();
                        if(listener != null){
                            listener.check(true,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;
    }

    public 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 TextView item_price;
        private final TextView item_des;
        private final CheckBox item_ck;
        private final Button del;

        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);
            item_price = itemView.findViewById(R.id.item_price);
            item_des = itemView.findViewById(R.id.item_des);
            del = itemView.findViewById(R.id.delete);
        }
    }
}

//CarBean
public class CarBean {
    private int pic;
    private String name;
    private int price;
    private boolean b=true;
    private long count;

    public CarBean(int pic, String name, int price, boolean isSelect, long count) {
        this.pic = pic;
        this.name = name;
        this.price = price;
        this.b = isSelect;
        this.count = count;
    }

    public int getPic() {
        return pic;
    }

    public void setPic(int pic) {
        this.pic = pic;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    public int getPrice() {
        return price;
    }

    public void setPrice(int price) {
        this.price = price;
    }

    public boolean isB() {
        return b;
    }

    public void setB(boolean b) {
        this.b = b;
    }

    public long getCount() {
        return count;
    }

    public void setCount(long count) {
        this.count = count;
    }
}

//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;

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, "最小数量为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);
            }

            @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;
    }
    public interface ChangeListener{
        public void onChange(long count);
    }
}

import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.CheckBox;
import android.widget.TextView;

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

public class MainActivity extends AppCompatActivity {
    private CheckBox checkBox;
    private TextView all_price;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        checkBox = (CheckBox) findViewById(R.id.ck_all);
        RecyclerView recyclerView = (RecyclerView) findViewById(R.id.rv_car);
        all_price = (TextView) findViewById(R.id.all_price);


        LinearLayoutManager manager = new LinearLayoutManager(this);
        recyclerView.setLayoutManager(manager);
        //添加死数据
        final List<CarBean> list = new ArrayList<>();
        for (int i = 0; i < 5; i++) {
            list.add(new CarBean(R.mipmap.ic_launcher_round,"商品" + i, 100, true, 1));
        }
        final CarAdapter adapter = new CarAdapter(this, list);
        recyclerView.setAdapter(adapter);


        adapter.setCheckListener(new CarAdapter.CheckListener() {
            @Override
            public void check(boolean check, int position) {
                //监听全选
                boolean all_check = true;
                //价格
                float price = 0;
                int count = 0;
                for (int i = 0; i < list.size(); i++) {
                    if (list.get(i).isB()) {
                        price += list.get(i).getPrice() * list.get(i).getCount();
                        count += list.get(i).getCount();
                    }
                }
                all_price.setText("共计"+count+"件，总共"+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;
                int count = 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();
                        count +=list.get(i).getCount();
                    }
                }
                adapter.notifyDataSetChanged();
                all_price.setText("共计"+count+"件，总共"+price + "元");
            }
        });
    }
}

//activity_main.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical"
    >
    <TextView
        android:text="购物车"
        android:textSize="28sp"
        android:layout_gravity="center"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

    <android.support.v7.widget.RecyclerView
        android:id="@+id/rv_car"
        android:layout_width="match_parent"
        android:layout_height="0dp"
        android:layout_weight="1"/>
    <LinearLayout
        android:orientation="horizontal"
        android:layout_width="match_parent"
        android:layout_height="30dp">
        <CheckBox
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="wrap_content"
            android:text="全选"
            android:checked="true"
            android:layout_gravity="center"
            android:id="@+id/ck_all"/>
        <TextView
            android:layout_width="0dp"
            android:layout_weight="1"
            android:layout_height="match_parent"
            android:text="总计5件，总价500元"
            android:layout_marginLeft="10dp"
            android:textSize="10sp"
            android:gravity="center_vertical"
            android:id="@+id/all_price"
            />
    </LinearLayout>

</LinearLayout>

//car_item.xml
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="130dp">
    <CheckBox
        android:id="@+id/item_ck"
        android:layout_centerVertical="true"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />
    <ImageView
        android:id="@+id/car_img"
        android:layout_toRightOf="@id/item_ck"
        android:src="@mipmap/ic_launcher"
        android:layout_margin="5dp"
        android:layout_width="60dp"
        android:layout_centerVertical="true"
        android:layout_height="60dp" />
    <TextView
        android:id="@+id/item_name"
        android:layout_toRightOf="@id/car_img"
        android:layout_width="wrap_content"
        android:text="111"
        android:layout_marginTop="30dp"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/item_price"
        android:layout_toRightOf="@id/car_img"
        android:layout_width="wrap_content"
        android:text="111"
        android:layout_below="@id/item_name"
        android:layout_height="wrap_content" />
    <com.example.mycar.CustomView
        android:id="@+id/item_custom"
        android:layout_below="@id/item_price"
        android:layout_toRightOf="@id/car_img"
        android:layout_width="70dp"
        android:layout_height="70dp"/>
    <Button
        android:id="@+id/delete"
        android:layout_alignParentRight="true"
        android:layout_margin="5dp"
        android:text="删除"
        android:layout_centerVertical="true"
        android:layout_width="40dp"
        android:layout_height="wrap_content" />
    <TextView
        android:id="@+id/item_des"
        android:layout_alignParentBottom="true"
        android:layout_toRightOf="@id/car_img"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" />

</RelativeLayout>

//  custom_layout.xml
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">
    <Button
        android:layout_width="30dp"
        android:layout_height="30dp"
        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="30dp"
        android:layout_height="30dp"
        android:background="#fff"
        android:text="+"
        android:id="@+id/jia"/>

</LinearLayout>