Android 购物车页面和逻辑实现

距离上次写第一篇博客已经好久了,今天正好有时间就来写一篇关于最近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!



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



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



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_h
f09a
eight="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

1.

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。

2.

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----->http://download.csdn.net/detail/u011011744/9706870