Android UI交互Android技术知识

Android 购物车页面和逻辑实现

2017-09-19  本文已影响296人  一只正在路上的程序员

之前在CSDN上写了几篇..现在想在简书上也写写,所以就过来试试....嘻嘻嘻~~~好,,进入正题....

这是之前在做的项目中的一个功能 购物车! 我这个购物车业务逻辑还算可以吧,不算太难,但由于我是第一次做,所以也碰到了很多细节上的问题...所以我想总结下来,方便以后学习和使用..好了先看看效果吧!


20161209152143632.gif

目前我做的功能除了结算就这些了...
下面开始来看代码
Activity界面是这样的


image.png
首先是Activity 布局xml
<?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">  
  
    <include  
        android:id="@+id/shopping_title"  
        layout="@layout/layout_title" />  
  
    <TextView  
        android:id="@+id/tv_edit"  
        android:layout_width="wrap_content"  
        android:layout_height="25dp"  
        android:layout_gravity="right"  
        android:layout_margin="10dp"  
        android:text="编辑"  
        android:textSize="18dp" />  
  
  
    <View  
        android:layout_width="match_parent"  
        android:layout_height="1dp"  
        android:layout_below="@id/tv_edit"  
        android:background="@color/gray3" />  
  
  
    <ListView  
        android:id="@+id/list_shopping_cart"  
        android:layout_width="match_parent"  
        android:layout_height="0dp"  
        android:layout_below="@id/tv_edit"  
        android:layout_weight="1"  
        android:scrollbars="none" />  
  
    <View  
        android:layout_width="match_parent"  
        android:layout_height="1dp"  
        android:background="@color/gray3" />  
  
    <RelativeLayout  
        android:id="@+id/rl_bottom"  
        android:layout_width="match_parent"  
        android:layout_height="50dp"  
        android:layout_alignParentBottom="true"  
        android:background="@color/white">  
  
  
        <CheckBox  
        android:id="@+id/ck_all"  
        android:layout_width="wrap_content"  
        android:layout_height="match_parent"  
        android:layout_centerVertical="true"  
        android:button="@drawable/check_box_style"  
        android:checkMark="?android:attr/listChoiceIndicatorMultiple"  
        android:gravity="center"  
        android:paddingLeft="10dp"  
        android:scaleX="0.6"  
        android:scaleY="0.6"  
        android:text="全选"  
        android:textAppearance="?android:attr/textAppearanceLarge"  
        android:textColor="@color/desccolor" />  
  
        <TextView  
            android:id="@+id/tv_settlement"  
            android:layout_width="80dp"  
            android:layout_height="match_parent"  
            android:layout_alignParentRight="true"  
            android:background="@color/desccolor"  
            android:gravity="center"  
            android:text="结算(0)"  
            android:textColor="@color/white" />  
  
        <TextView  
            android:id="@+id/tv_show_price"  
            android:layout_width="wrap_content"  
            android:layout_height="match_parent"  
            android:layout_toLeftOf="@id/tv_settlement"  
            android:gravity="center"  
            android:padding="5dp"  
            android:text="合计:0.00"  
            android:textColor="@color/desccolor" />  
    </RelativeLayout>  
</LinearLayout>  

再来看 ListView item的布局


image.png

item 布局xml

<?xml version="1.0" encoding="utf-8"?>  
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"  
    android:layout_width="match_parent"  
    android:layout_height="190dp"  
    android:orientation="vertical">  
  
    <CheckBox  
        android:id="@+id/ck_chose"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_centerVertical="true"  
        android:layout_marginLeft="8dp"  
        android:button="@drawable/check_box_style"  
        android:scaleX="0.6"  
        android:scaleY="0.6" />  
  
    <ImageView  
        android:id="@+id/iv_show_pic"  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_centerVertical="true"  
        android:layout_marginLeft="10dp"  
        android:layout_toRightOf="@id/ck_chose"  
        android:background="@mipmap/demo" />  
  
    <LinearLayout  
        android:layout_width="wrap_content"  
        android:layout_height="wrap_content"  
        android:layout_marginLeft="15dp"  
        android:layout_marginTop="30dp"  
        android:layout_toRightOf="@id/iv_show_pic"  
        android:orientation="vertical">  
  
        <TextView  
            android:id="@+id/tv_commodity_name"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
  
            android:text="酒红色纯红色纯羊毛西服套装"  
            android:textColor="@color/black"  
            android:textStyle="bold" />  
  
        <RelativeLayout  
            android:id="@+id/rl_edit"  
            android:layout_width="110dp"  
            android:layout_height="30dp"  
            android:orientation="horizontal"  
            android:visibility="gone">  
  
            <ImageView  
                android:id="@+id/iv_sub"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:background="@mipmap/iv_sub" />  
  
            <TextView  
                android:id="@+id/tv_show_num"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_centerHorizontal="true"  
                android:layout_centerVertical="true"  
                android:text="1"  
                android:textColor="@color/desccolor" />  
  
            <ImageView  
                android:id="@+id/iv_add"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_alignParentRight="true"  
                android:background="@mipmap/iv_add" />  
  
            <View  
                android:layout_width="match_parent"  
                android:layout_height="0.7dp"  
                android:layout_alignParentBottom="true"  
                android:background="@color/black" />  
        </RelativeLayout>  
  
  
        <TextView  
            android:id="@+id/tv_fabric"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_marginTop="10dp"  
            android:text="面料:"  
            android:textColor="@color/gray5" />  
  
        <LinearLayout  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:orientation="horizontal">  
  
            <TextView  
                android:id="@+id/tv_dress"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_marginTop="10dp"  
                android:text="西服尺寸: 48"  
                android:textColor="@color/gray5" />  
  
        </LinearLayout>  
  
  
        <TextView  
            android:id="@+id/tv_pants"  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_marginTop="10dp"  
            android:text="西裤尺寸: 68"  
            android:textColor="@color/gray5" />  
  
        <LinearLayout  
            android:layout_width="wrap_content"  
            android:layout_height="wrap_content"  
            android:layout_marginTop="10dp"  
            android:orientation="horizontal">  
  
            <TextView  
                android:id="@+id/tv_price"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:text="¥390"  
                android:textColor="@color/black"  
                android:textStyle="bold" />  
  
  
            <TextView  
                android:id="@+id/tv_num"  
                android:layout_width="wrap_content"  
                android:layout_height="wrap_content"  
                android:layout_marginLeft="40dp"  
                android:text="x1"  
                android:textColor="@color/gray5" />  
        </LinearLayout>  
    </LinearLayout>  
  
    <TextView  
        android:id="@+id/tv_delete"  
        android:layout_width="60dp"  
        android:layout_height="match_parent"  
        android:layout_alignParentRight="true"  
        android:background="@color/address_press"  
        android:gravity="center"  
        android:text="删除"  
        android:visibility="gone" />  
  
</RelativeLayout>  

好了 ,,布局就说完了 现在我们来看看逻辑部分
由于很多操作是在Activity中操作 ListView的item ,所以我这里选择的是接口回调,我感觉方便些..也许你会有更好的方法.
首先我们在 Adapter中定义了几个

/** 
 * 复选框接口 
 */  
public interface CheckInterface {  
    /** 
     * 组选框状态改变触发的事件 
     * 
     * @param position  元素位置 
     * @param isChecked 元素选中与否 
     */  
    void checkGroup(int position, boolean isChecked);  
}  
  
  
/** 
 * 改变数量的接口 
 */  
public interface ModifyCountInterface {  
    /** 
     * 增加操作 
     * 
     * @param position      组元素位置 
     * @param showCountView 用于展示变化后数量的View 
     * @param isChecked     子元素选中与否 
     */  
    void doIncrease(int position, View showCountView, boolean isChecked);  
  
    /** 
     * 删减操作 
     * 
     * @param position      组元素位置 
     * @param showCountView 用于展示变化后数量的View 
     * @param isChecked     子元素选中与否 
     */  
    void doDecrease(int position, View showCountView, boolean isChecked);  
  
    /** 
     * 删除子item 
     * 
     * @param position 
     */  
    void childDelete(int position);  
}  

再来看看Adapter 没啥可说的.. 注释我在代码写的还算详细 ,相信能看懂

public class ShoppingCartAdapter extends BaseAdapter {  
  
    private boolean isShow = true;//是否显示编辑/完成  
    private List<ShoppingCartBean> shoppingCartBeanList;  
    private CheckInterface checkInterface;  
    private ModifyCountInterface modifyCountInterface;  
    private Context context;  
  
    public ShoppingCartAdapter(Context context) {  
        this.context = context;  
    }  
  
    public void setShoppingCartBeanList(List<ShoppingCartBean> shoppingCartBeanList) {  
        this.shoppingCartBeanList = shoppingCartBeanList;  
        notifyDataSetChanged();  
    }  
  
    /** 
     * 单选接口 
     * 
     * @param checkInterface 
     */  
    public void setCheckInterface(CheckInterface checkInterface) {  
        this.checkInterface = checkInterface;  
    }  
  
    /** 
     * 改变商品数量接口 
     * 
     * @param modifyCountInterface 
     */  
    public void setModifyCountInterface(ModifyCountInterface modifyCountInterface) {  
        this.modifyCountInterface = modifyCountInterface;  
    }  
  
    @Override  
    public int getCount() {  
        return shoppingCartBeanList == null ? 0 : shoppingCartBeanList.size();  
    }  
  
    @Override  
    public Object getItem(int position) {  
        return shoppingCartBeanList.get(position);  
    }  
  
    @Override  
    public long getItemId(int position) {  
        return position;  
    }  
  
  
    /** 
     * 是否显示可编辑 
     * 
     * @param flag 
     */  
    public void isShow(boolean flag) {  
        isShow = flag;  
        notifyDataSetChanged();  
    }  
  
    @Override  
    public View getView(final int position, View convertView, ViewGroup parent) {  
  
        final ViewHolder holder;  
        if (convertView == null) {  
            convertView = LayoutInflater.from(context).inflate(R.layout.item_shopping_cart_layout, parent, false);  
            holder = new ViewHolder(convertView);  
            convertView.setTag(holder);  
        } else {  
            holder = (ViewHolder) convertView.getTag();  
        }  
        final ShoppingCartBean shoppingCartBean = shoppingCartBeanList.get(position);  
        holder.tv_commodity_name.setText(shoppingCartBean.getShoppingName());  
        holder.tv_fabric.setText("面料:" + shoppingCartBean.getFabric());  
        holder.tv_dress.setText("西服尺寸:" + shoppingCartBean.getDressSize());  
        holder.tv_pants.setText("西裤尺寸:" + shoppingCartBean.getPantsSize());  
        holder.tv_price.setText("¥:" + shoppingCartBean.getPrice());  
        holder.ck_chose.setChecked(shoppingCartBean.isChoosed());  
        holder.tv_show_num.setText(shoppingCartBean.getCount() + "");  
        holder.tv_num.setText("X" + shoppingCartBean.getCount());  
  
        //单选框按钮  
        holder.ck_chose.setOnClickListener(  
                new View.OnClickListener() {  
                    @Override  
                    public void onClick(View v) {  
                        shoppingCartBean.setChoosed(((CheckBox) v).isChecked());  
                        checkInterface.checkGroup(position, ((CheckBox) v).isChecked());//向外暴露接口  
                    }  
                }  
        );  
  
        //增加按钮  
        holder.iv_add.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View v) {  
                modifyCountInterface.doIncrease(position, holder.tv_show_num, holder.ck_chose.isChecked());//暴露增加接口  
            }  
        });  
  
        //删减按钮  
        holder.iv_sub.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View v) {  
                modifyCountInterface.doDecrease(position, holder.tv_show_num, holder.ck_chose.isChecked());//暴露删减接口  
            }  
        });  
  
  
        //删除弹窗  
        holder.tv_delete.setOnClickListener(new View.OnClickListener() {  
            @Override  
            public void onClick(View v) {  
                AlertDialog alert = new AlertDialog.Builder(context).create();  
                alert.setTitle("操作提示");  
                alert.setMessage("您确定要将这些商品从购物车中移除吗?");  
                alert.setButton(DialogInterface.BUTTON_NEGATIVE, "取消",  
                        new DialogInterface.OnClickListener() {  
                            @Override  
                            public void onClick(DialogInterface dialog, int which) {  
                                return;  
                            }  
                        });  
                alert.setButton(DialogInterface.BUTTON_POSITIVE, "确定",  
                        new DialogInterface.OnClickListener() {  
                            @Override  
                            public void onClick(DialogInterface dialog, int which) {  
                                modifyCountInterface.childDelete(position);//删除 目前只是从item中移除  
  
                            }  
                        });  
                alert.show();  
            }  
        });  
  
        //判断是否在编辑状态下  
        if (isShow) {  
            holder.tv_commodity_name.setVisibility(View.VISIBLE);  
            holder.tv_fabric.setVisibility(View.VISIBLE);  
            holder.rl_edit.setVisibility(View.GONE);  
            holder.tv_delete.setVisibility(View.GONE);  
        } else {  
            holder.tv_commodity_name.setVisibility(View.GONE);  
            holder.tv_fabric.setVisibility(View.GONE);  
            holder.rl_edit.setVisibility(View.VISIBLE);  
            holder.tv_delete.setVisibility(View.VISIBLE);  
        }  
  
        return convertView;  
    }  
  
  
    //初始化控件  
    class ViewHolder {  
        ImageView iv_chose;  
        ImageView iv_show_pic, iv_sub, iv_add;  
        TextView tv_commodity_name, tv_fabric, tv_dress, tv_pants, tv_price, tv_num, tv_delete, tv_show_num;  
        CheckBox ck_chose;  
        RelativeLayout rl_edit;  
  
        public ViewHolder(View itemView) {  
            ck_chose = (CheckBox) itemView.findViewById(R.id.ck_chose);  
            iv_show_pic = (ImageView) itemView.findViewById(R.id.iv_show_pic);  
            iv_sub = (ImageView) itemView.findViewById(R.id.iv_sub);  
            iv_add = (ImageView) itemView.findViewById(R.id.iv_add);  
  
            tv_commodity_name = (TextView) itemView.findViewById(R.id.tv_commodity_name);  
            tv_fabric = (TextView) itemView.findViewById(R.id.tv_fabric);  
            tv_dress = (TextView) itemView.findViewById(R.id.tv_dress);  
            tv_pants = (TextView) itemView.findViewById(R.id.tv_pants);  
            tv_price = (TextView) itemView.findViewById(R.id.tv_price);  
            tv_num = (TextView) itemView.findViewById(R.id.tv_num);  
            tv_delete = (TextView) itemView.findViewById(R.id.tv_delete);  
            tv_show_num = (TextView) itemView.findViewById(R.id.tv_show_num);  
            rl_edit = (RelativeLayout) itemView.findViewById(R.id.rl_edit);  
  
        }  
  
    }

现在我们在来看看Activity 代码, 同样注释写的很详细

public class ShoppingCartActivity extends BaseActivity implements View.OnClickListener  
        , ShoppingCartAdapter.CheckInterface, ShoppingCartAdapter.ModifyCountInterface {  
    public TextView tv_title, tv_settlement, tv_show_price;  
    private TextView tv_all_check;  
    private CheckBox ck_all;  
    private ListView list_shopping_cart;  
    private ShoppingCartAdapter shoppingCartAdapter;  
    private TextView tv_edit;  
    private boolean flag = false;  
    private List<ShoppingCartBean> shoppingCartBeanList = new ArrayList<>();  
    private boolean mSelect;  
    private double totalPrice = 0.00;// 购买的商品总价  
    private int totalCount = 0;// 购买的商品总数量  
    /** 
     * 批量模式下,用来记录当前选中状态 
     */  
    private SparseArray<Boolean> mSelectState = new SparseArray<Boolean>();  
  
  
    @Override  
    protected int getLayout() {  
        return R.layout.layout_shopping_cart_activity;  
    }  
  
    @Override  
    protected void initView() {  
        tv_title = bindView(R.id.tv_title);  
        tv_title.setText("购物车");  
        list_shopping_cart = bindView(R.id.list_shopping_cart);  
//        list_shopping_cart.setOnItemClickListener(this);  
        ck_all = bindView(R.id.ck_all);  
        ck_all.setOnClickListener(this);  
//        ck_all.setOnCheckedChangeListener(this);  
        tv_show_price = bindView(R.id.tv_show_price);  
        tv_settlement = bindView(R.id.tv_settlement);  
        tv_settlement.setOnClickListener(this);  
        tv_edit = bindView(R.id.tv_edit);  
        tv_edit.setOnClickListener(this);  
        shoppingCartAdapter = new ShoppingCartAdapter(this);  
        shoppingCartAdapter.setCheckInterface(this);  
        shoppingCartAdapter.setModifyCountInterface(this);  
        list_shopping_cart.setAdapter(shoppingCartAdapter);  
        shoppingCartAdapter.setShoppingCartBeanList(shoppingCartBeanList);  
  
    }  
  
    @Override  
    protected void initData() {  
  
        for (int i = 0; i < 6; i++) {  
            ShoppingCartBean shoppingCartBean = new ShoppingCartBean();  
            shoppingCartBean.setShoppingName("高端大气上档次的T桖");  
            shoppingCartBean.setFabric("纯棉");  
            shoppingCartBean.setDressSize(48);  
            shoppingCartBean.setPantsSize(65);  
            shoppingCartBean.setPrice(60);  
            shoppingCartBean.setCount(2);  
            shoppingCartBeanList.add(shoppingCartBean);  
        }  
  
    }  
  
    @Override  
    public void onClick(View v) {  
        switch (v.getId()) {  
            //全选按钮    
            case R.id.ck_all:  
                if (shoppingCartBeanList.size() != 0) {  
                    if (ck_all.isChecked()) {  
                        for (int i = 0; i < shoppingCartBeanList.size(); i++) {  
                            shoppingCartBeanList.get(i).setChoosed(true);  
                        }  
                        shoppingCartAdapter.notifyDataSetChanged();  
                    } else {  
                        for (int i = 0; i < shoppingCartBeanList.size(); i++) {  
                            shoppingCartBeanList.get(i).setChoosed(false);  
                        }  
                        shoppingCartAdapter.notifyDataSetChanged();  
                    }  
                }  
                statistics();  
                break;  
            case R.id.tv_edit:  
                flag = !flag;  
                if (flag) {  
                    tv_edit.setText("完成");  
                    shoppingCartAdapter.isShow(false);  
                } else {  
                    tv_edit.setText("编辑");  
                    shoppingCartAdapter.isShow(true);  
                }  
                break;  
        }  
    }  
  
    /** 
     * 单选 
     * 
     * @param position  组元素位置 
     * @param isChecked 组元素选中与否 
     */  
    @Override  
    public void checkGroup(int position, boolean isChecked) {  
  
        shoppingCartBeanList.get(position).setChoosed(isChecked);  
  
        if (isAllCheck())  
            ck_all.setChecked(true);  
        else  
            ck_all.setChecked(false);  
  
        shoppingCartAdapter.notifyDataSetChanged();  
        statistics();  
    }  
  
  
    /** 
     * 遍历list集合 
     * 
     * @return 
     */  
    private boolean isAllCheck() {  
  
        for (ShoppingCartBean group : shoppingCartBeanList) {  
            if (!group.isChoosed())  
                return false;  
        }  
        return true;  
    }  
  
    /** 
     * 统计操作 
     * 1.先清空全局计数器<br> 
     * 2.遍历所有子元素,只要是被选中状态的,就进行相关的计算操作 
     * 3.给底部的textView进行数据填充 
     */  
    public void statistics() {  
        totalCount = 0;  
        totalPrice = 0.00;  
        for (int i = 0; i < shoppingCartBeanList.size(); i++) {  
            ShoppingCartBean shoppingCartBean = shoppingCartBeanList.get(i);  
            if (shoppingCartBean.isChoosed()) {  
                totalCount++;  
                totalPrice += shoppingCartBean.getPrice() * shoppingCartBean.getCount();  
            }  
        }  
        tv_show_price.setText("合计:" + totalPrice);  
        tv_settlement.setText("结算(" + totalCount + ")");  
    }  
  
    /** 
     * 增加 
     * 
     * @param position      组元素位置 
     * @param showCountView 用于展示变化后数量的View 
     * @param isChecked     子元素选中与否 
     */  
    @Override  
    public void doIncrease(int position, View showCountView, boolean isChecked) {  
        ShoppingCartBean shoppingCartBean = shoppingCartBeanList.get(position);  
        int currentCount = shoppingCartBean.getCount();  
        currentCount++;  
        shoppingCartBean.setCount(currentCount);  
        ((TextView) showCountView).setText(currentCount + "");  
        shoppingCartAdapter.notifyDataSetChanged();  
        statistics();  
    }  
  
    /** 
     * 删减 
     * 
     * @param position      组元素位置 
     * @param showCountView 用于展示变化后数量的View 
     * @param isChecked     子元素选中与否 
     */  
    @Override  
    public void doDecrease(int position, View showCountView, boolean isChecked) {  
        ShoppingCartBean shoppingCartBean = shoppingCartBeanList.get(position);  
        int currentCount = shoppingCartBean.getCount();  
        if (currentCount == 1) {  
            return;  
        }  
        currentCount--;  
        shoppingCartBean.setCount(currentCount);  
        ((TextView) showCountView).setText(currentCount + "");  
        shoppingCartAdapter.notifyDataSetChanged();  
        statistics();  
  
    }  
  
    /** 
     * 删除 
     * 
     * @param position 
     */  
    @Override  
    public void childDelete(int position) {  
        shoppingCartBeanList.remove(position);  
        shoppingCartAdapter.notifyDataSetChanged();  
        statistics();  
  
    }  
  
}  

整体的就是这样,,我说一下 我做的时候遇到的问题和解决办法

问题:当我单选一个一个选中后,全选按钮也会自动选中 ,但是当我取消一个item后 全选按钮没有自动取消 (正常是只有有一个item没有选中 全选按钮是不会选中的)
解决:首先解决问题要找到原因所在 ,造成这个Bug的原因是我CheckBox的点击事件用的是setOnCheckedChangeListener 后来换成了setOnClickListener 就好了 .
两者都能实现对CheckBox的状态改变的监听,但一般情况下,用的更多的是setOnCheckedChangeListener。因为,当CheckBox的状态不是通过点击事件改变,而是通过其他的方式改变时,比如setCheck(),setOnClickListener无法完成此种情况下的监听。OnCheckChangedListener监听CheckBox的状态,无论来自你的onClick事件还是其他。

问题: 就是在改变物品个数的是时候会出现复用!
解决: 原因就是我没有保存当前 改变后是值, 保存一下就OK了..

总体上就是这些了.......感兴趣的同学可以下载demo看看

Demo在这里----->https://github.com/HelloSinger/ShoppingCat
(第一次在github上上传项目,还不是很熟悉项目展示有点问题,不过不影响下载,我之后再改改)

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