Android实现简单购物车功能

<?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"
  android:orientation="vertical" >

  <linearlayout
    android:id="@+id/top_bar"
    android:layout_width="match_parent"
    android:layout_height="48dp"
    android:background="#e24146"
    android:orientation="vertical" >
    <textview
      android:id="@+id/title"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:gravity="center"
      android:minheight="48dp"
      android:text="购物车"
      android:textcolor="#ffffff"
      android:textsize="17sp" />
  </linearlayout>

  <listview
    android:id="@+id/listview"
    android:layout_width="match_parent"
    android:layout_height="0dp"
    android:layout_weight="1"
    android:childindicator="@null"
    android:groupindicator="@null" >
  </listview>

  <linearlayout
    android:layout_width="match_parent"
    android:layout_height="50dp"
    android:orientation="horizontal" >

    <linearlayout
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_weight="2.5"
      android:gravity="center_vertical"
      android:orientation="horizontal" >

      <checkbox
        android:id="@+id/all_chekbox"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_gravity="center_vertical"
        android:layout_marginleft="10dp"
        android:layout_marginright="4dp"
        android:button="@drawable/check_box_bg"
        android:checkmark="?android:attr/listchoiceindicatormultiple"
        android:gravity="center"
        android:minheight="64dp"
        android:paddingleft="10dp"
        android:textappearance="?android:attr/textappearancelarge"
        android:visibility="visible" />

      <textview
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_marginleft="5dp"
        android:text="合计:"
        android:textsize="16sp"
        android:textstyle="bold" />

      <textview
        android:id="@+id/tv_total_price"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="￥0.00"
        android:textcolor="@color/purple"
        android:textsize="16sp"
        android:textstyle="bold" />
    </linearlayout>

    <textview
      android:id="@+id/tv_delete"
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_weight="1"
      android:background="@color/orange"
      android:clickable="true"
      android:gravity="center"
      android:text="删除"
      android:textcolor="#fafafa" />

    <textview
      android:id="@+id/tv_go_to_pay"
      android:layout_width="0dp"
      android:layout_height="match_parent"
      android:layout_weight="1"
      android:background="#e24146"
      android:clickable="true"
      android:gravity="center"
      android:text="付款(0)"
      android:textcolor="#fafafa" />
  </linearlayout>

</linearlayout>

import android.os.bundle;
import android.support.v7.app.appcompatactivity;
import android.view.view;
import android.widget.checkbox;
import android.widget.listview;
import android.widget.textview;
import android.widget.toast;

import java.util.arraylist;
import java.util.hashmap;
import java.util.iterator;
import java.util.list;
import java.util.map;
import java.util.random;

public class mainactivity extends appcompatactivity implements cartadapter.refreshpriceinterface ,view.onclicklistener{

  private listview listview;
  private checkbox cb_check_all;
  private textview tv_total_price;
  private textview tv_delete;
  private textview tv_go_to_pay;

  private cartadapter adapter;

  private double totalprice = 0.00;
  private int totalcount = 0;
  private list<hashmap<string,string>> goodslist;

  @override
  protected void oncreate(bundle savedinstancestate) {
    super.oncreate(savedinstancestate);
    setcontentview(r.layout.activity_main);

    initdate();
  }

  //控制价格展示
  private void pricecontrol(map<string, integer> pitchonmap){
    totalcount = 0;
    totalprice = 0.00;
    for(int i=0;i<goodslist.size();i++){
      if(pitchonmap.get(goodslist.get(i).get("id"))==1){
        totalcount=totalcount+integer.valueof(goodslist.get(i).get("count"));
        double goodsprice=integer.valueof(goodslist.get(i).get("count"))*double.valueof(goodslist.get(i).get("price"));
        totalprice=totalprice+goodsprice;
      }
    }
    tv_total_price.settext("￥ "+totalprice);
    tv_go_to_pay.settext("付款("+totalcount+")");
  }

  @override
  public void refreshprice(map<string, integer> pitchonmap) {
    pricecontrol(pitchonmap);
  }

  @override
  public void onclick(view view) {
    switch (view.getid()){
      case r.id.all_chekbox:
        alltheselected();
        break;
      case r.id.tv_go_to_pay:
        if(totalcount<=0){
          toast.maketext(this,"请选择要付款的商品~",toast.length_short).show();
          return;
        }
        toast.maketext(this,"钱就是另一回事了~",toast.length_short).show();
        break;
      case r.id.tv_delete:
        if(totalcount<=0){
          toast.maketext(this,"请选择要删除的商品~",toast.length_short).show();
          return;
        }
        checkdelete(adapter.getpitchonmap());
        break;
    }
  }

  //删除操作
  private void checkdelete(map<string,integer> map){
    list<hashmap<string,string>> waitdeletelist=new arraylist<>();
    map<string,integer> waitdeletemap =new hashmap<>();
    for(int i=0;i<goodslist.size();i++){
      if(map.get(goodslist.get(i).get("id"))==1){
        waitdeletelist.add(goodslist.get(i));
        waitdeletemap.put(goodslist.get(i).get("id"),map.get(goodslist.get(i).get("id")));
      }
    }
    goodslist.removeall(waitdeletelist);
    map.remove(waitdeletemap);
    pricecontrol(map);
    adapter.notifydatasetchanged();
  }

  //全选或反选
  private void alltheselected(){
    map<string,integer> map=adapter.getpitchonmap();
    boolean ischeck=false;
    boolean isuncheck=false;
    iterator iter = map.entryset().iterator();
    while (iter.hasnext()) {
      map.entry entry = (map.entry) iter.next();
      if(integer.valueof(entry.getvalue().tostring())==1)ischeck=true;
      else isuncheck=true;
    }
    if(ischeck==true&&isuncheck==false){//已经全选,做反选
      for(int i=0;i<goodslist.size();i++){
        map.put(goodslist.get(i).get("id"),0);
      }
      cb_check_all.setchecked(false);
    }else if(ischeck==true && isuncheck==true){//部分选择,做全选
      for(int i=0;i<goodslist.size();i++){
        map.put(goodslist.get(i).get("id"),1);
      }
      cb_check_all.setchecked(true);
    }else if(ischeck==false && isuncheck==true){//一个没选,做全选
      for(int i=0;i<goodslist.size();i++){
        map.put(goodslist.get(i).get("id"),1);
      }
      cb_check_all.setchecked(true);
    }
    pricecontrol(map);
    adapter.setpitchonmap(map);
    adapter.notifydatasetchanged();
  }

  private void initview(){
    listview = (listview) findviewbyid(r.id.listview);
    cb_check_all = (checkbox) findviewbyid(r.id.all_chekbox);
    tv_total_price = (textview) findviewbyid(r.id.tv_total_price);
    tv_delete = (textview) findviewbyid(r.id.tv_delete);
    tv_go_to_pay = (textview) findviewbyid(r.id.tv_go_to_pay);
    tv_go_to_pay.setonclicklistener(this);
    tv_delete.setonclicklistener(this);
    cb_check_all.setonclicklistener(this);

    adapter=new cartadapter(this,goodslist);
    adapter.setrefreshpriceinterface(this);
    listview.setadapter(adapter);
    adapter.notifydatasetchanged();
  }

  private void initdate(){
    goodslist=new arraylist<>();
    for(int i=0;i<10;i++){
      hashmap<string,string> map=new hashmap<>();
      map.put("id",(new random().nextint(10000)%(10000-2900+2900) + 2900)+"");
      map.put("name","购物车里的第"+(i+1)+"件商品");
      map.put("type",(i+20)+"码");
      map.put("price",(new random().nextint(100)%(100-29+29) + 29)+"");
      map.put("count",(new random().nextint(10)%(10-1+1) + 1)+"");
      goodslist.add(map);
    }

    initview();
  }
}

<linearlayout xmlns:android="http://schemas.android.com/apk/res/android"
  android:layout_width="match_parent"
  android:layout_height="wrap_content"
  android:orientation="vertical" >

  <view
    android:layout_width="match_parent"
    android:layout_height="1dp"
    android:background="#cccccc" />

  <linearlayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:background="@color/page_backgroup"
    android:orientation="horizontal" >

    <checkbox
      android:id="@+id/check_box"
      android:layout_width="wrap_content"
      android:layout_height="wrap_content"
      android:layout_gravity="center_vertical"
      android:layout_marginleft="10dp"
      android:layout_marginright="4dp"
      android:button="@drawable/check_box_bg"
      android:checkmark="?android:attr/listchoiceindicatormultiple"
      android:gravity="center"
      android:minheight="64dp"
      android:minwidth="32dp"
      android:textappearance="?android:attr/textappearancelarge"
      android:visibility="visible" />

    <imageview
      android:id="@+id/iv_adapter_list_pic"
      android:layout_width="85dp"
      android:layout_height="85dp"
      android:layout_marginbottom="15dp"
      android:layout_margintop="13dp"
      android:scaletype="centercrop"
      android:src="@mipmap/good_icon" />

    <relativelayout
      android:layout_width="wrap_content"
      android:layout_height="match_parent"
      android:layout_gravity="center_vertical"
      android:layout_margintop="10dp"
      android:layout_marginleft="13dp" >

      <textview
        android:id="@+id/tv_goods_name"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_marginright="10dp"
        android:layout_margintop="20dp"
        android:ellipsize="end"
        android:maxlines="2"
        android:textcolor="@color/grey_color1"
        android:textsize="14sp" />

      <relativelayout
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:layout_alignparentbottom="true"
        android:layout_marginbottom="30dp"
        android:orientation="horizontal" >

        <textview
          android:id="@+id/tv_goods_price"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_centervertical="true"
          android:singleline="true"
          android:textcolor="@color/orange_color"
          android:textsize="14sp"
          android:textstyle="bold" />

        <textview
          android:id="@+id/tv_type_size"
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_centervertical="true"
          android:layout_marginleft="10dp"
          android:layout_torightof="@+id/tv_goods_price"
          android:singleline="true"
          android:textcolor="@color/grey_color3"
          android:textsize="10sp"/>

        <linearlayout
          android:layout_width="wrap_content"
          android:layout_height="wrap_content"
          android:layout_alignparentright="true"
          android:layout_centervertical="true"
          android:layout_marginright="15dp"
          android:orientation="horizontal" >

          <textview
            android:id="@+id/tv_reduce"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:background="@drawable/text_angle_gray"
            android:gravity="center"
            android:text="一"
            android:textcolor="@color/grey_color1"
            android:textsize="12sp" />

          <textview
            android:id="@+id/tv_num"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:background="@drawable/text_angle"
            android:gravity="center"
            android:singleline="true"
            android:text="1"
            android:textcolor="@color/grey_color1"
            android:textsize="12sp" />

          <textview
            android:id="@+id/tv_add"
            android:layout_width="25dp"
            android:layout_height="25dp"
            android:background="@drawable/text_angle_right"
            android:gravity="center"
            android:text="+"
            android:textcolor="@color/grey_color1"
            android:textsize="12sp" />
        </linearlayout>
      </relativelayout>
    </relativelayout>
  </linearlayout>

</linearlayout>

import android.content.context;
import android.view.layoutinflater;
import android.view.view;
import android.view.viewgroup;
import android.widget.baseadapter;
import android.widget.checkbox;
import android.widget.imageview;
import android.widget.textview;
import android.widget.toast;

import java.util.hashmap;
import java.util.list;
import java.util.map;

/**
 * created by lipeng
 * 2017/6/5.
 */

public class cartadapter extends baseadapter {

  private context context;
  private list<hashmap<string,string>> datalist;
  private viewholder vh;
  private map<string,integer> pitchonmap;
  private refreshpriceinterface refreshpriceinterface;

  public cartadapter(context context, list<hashmap<string,string>> list){
    this.context=context;
    this.datalist=list;

    pitchonmap=new hashmap<>();
    for(int i=0;i<datalist.size();i++){
      pitchonmap.put(datalist.get(i).get("id"),0);
    }
  }

  @override
  public view getview(final int position, view view, viewgroup viewgroup) {
    vh=new viewholder();
    if(view==null){
      view= layoutinflater.from(context).inflate(r.layout.item_layout,null);

      vh.checkbox=(checkbox)view.findviewbyid(r.id.check_box);
      vh.icon=(imageview)view.findviewbyid(r.id.iv_adapter_list_pic);
      vh.name=(textview)view.findviewbyid(r.id.tv_goods_name);
      vh.price=(textview)view.findviewbyid(r.id.tv_goods_price);
      vh.type=(textview)view.findviewbyid(r.id.tv_type_size);
      vh.num=(textview)view.findviewbyid(r.id.tv_num);
      vh.reduce=(textview)view.findviewbyid(r.id.tv_reduce);
      vh.add=(textview)view.findviewbyid(r.id.tv_add);

      view.settag(vh);
    }else {
      vh=(viewholder)view.gettag();
    }

    if(datalist.size()>0){

      if(pitchonmap.get(datalist.get(position).get("id"))==0)vh.checkbox.setchecked(false);
      else vh.checkbox.setchecked(true);
      hashmap<string,string> map=datalist.get(position);
      vh.name.settext(map.get("name"));
      vh.num.settext(map.get("count"));
      vh.type.settext(map.get("type"));
      vh.price.settext("￥ "+(double.valueof(map.get("price")) * integer.valueof(map.get("count"))));

      vh.checkbox.setonclicklistener(new view.onclicklistener() {
        @override
        public void onclick(view view) {
          final int index=position;
          if(((checkbox)view).ischecked())pitchonmap.put(datalist.get(index).get("id"),1);else pitchonmap.put(datalist.get(index).get("id"),0);
          refreshpriceinterface.refreshprice(pitchonmap);
        }
      });
      vh.reduce.setonclicklistener(new view.onclicklistener() {
        @override
        public void onclick(view view) {
          final int index=position;
          datalist.get(index).put("count",(integer.valueof(datalist.get(index).get("count"))-1)+"");
          if(integer.valueof(datalist.get(index).get("count"))<=0){
            //可提示是否删除该商品,确定就remove,否则就保留1
            string deid=datalist.get(index).get("id");
            datalist.remove(index);
            pitchonmap.remove(deid);
          }
          notifydatasetchanged();
          refreshpriceinterface.refreshprice(pitchonmap);
        }
      });
      vh.add.setonclicklistener(new view.onclicklistener() {
        @override
        public void onclick(view view) {
          final int index=position;
          datalist.get(index).put("count",(integer.valueof(datalist.get(index).get("count"))+1)+"");
          if(integer.valueof(datalist.get(index).get("count"))>15){
            //15为库存可选择上限
            toast.maketext(context,"已达库存上限~",toast.length_short).show();
            return;
          }
          notifydatasetchanged();
          refreshpriceinterface.refreshprice(pitchonmap);
        }
      });
    }

    return view;
  }

  public map<string,integer> getpitchonmap(){
    return pitchonmap;
  }
  public void setpitchonmap(map<string,integer> pitchonmap){
    this.pitchonmap=new hashmap<>();
    this.pitchonmap.putall(pitchonmap);
  }

  public interface refreshpriceinterface{
    void refreshprice(map<string, integer> pitchonmap);
  }
  public void setrefreshpriceinterface(refreshpriceinterface refreshpriceinterface){
    this.refreshpriceinterface=refreshpriceinterface;
  }

  @override
  public object getitem(int i) {
    return null;
  }

  @override
  public long getitemid(int i) {
    return 0;
  }

  @override
  public int getcount() {
    if (datalist != null) {
      return datalist.size();
    } else {
      return 0;
    }
  }

  class viewholder{
    checkbox checkbox;
    imageview icon;
    textview name,price,num,type,reduce,add;
  }
}