转自: http://blog.youkuaiyun.com/u014061684/article/details/50608588
前面有篇文章实现了Android 简单的购物车 这篇实现了购物车中商品按照店铺分类显示的 也就是淘宝购物车的显示方式。
主要代码
- package com.jock.shopcart;
- import java.util.ArrayList;
- import java.util.HashMap;
- import java.util.List;
- import java.util.Map;
- import android.app.Activity;
- import android.app.AlertDialog;
- import android.content.Context;
- import android.content.DialogInterface;
- import android.os.Bundle;
- import android.view.View;
- import android.view.View.OnClickListener;
- import android.view.Window;
- import android.widget.CheckBox;
- import android.widget.ExpandableListView;
- import android.widget.TextView;
- import android.widget.Toast;
- import com.jock.adapter.ShopcartExpandableListViewAdapter;
- import com.jock.adapter.ShopcartExpandableListViewAdapter.CheckInterface;
- import com.jock.adapter.ShopcartExpandableListViewAdapter.ModifyCountInterface;
- import com.jock.entity.GroupInfo;
- import com.jock.entity.ProductInfo;
- import com.jock.shopcar.R;
- public class MainActivity extends Activity implements CheckInterface, ModifyCountInterface, OnClickListener
- {
- private ExpandableListView exListView;
- private CheckBox cb_check_all;
- private TextView tv_total_price;
- private TextView tv_delete;
- private TextView tv_go_to_pay;
- private Context context;
- private double totalPrice = 0.00;// 购买的商品总价
- private int totalCount = 0;// 购买的商品总数量
- private ShopcartExpandableListViewAdapter selva;
- private List<GroupInfo> groups = new ArrayList<GroupInfo>();// 组元素数据列表
- private Map<String, List<ProductInfo>> children = new HashMap<String, List<ProductInfo>>();// 子元素数据列表
- @Override
- protected void onCreate(Bundle savedInstanceState)
- {
- super.onCreate(savedInstanceState);
- requestWindowFeature(Window.FEATURE_NO_TITLE);
- setContentView(R.layout.activity_main);
- initView();
- initEvents();
- }
- private void initView()
- {
- context = this;
- virtualData();
- exListView = (ExpandableListView) findViewById(R.id.exListView);
- 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);
- }
- private void initEvents()
- {
- selva = new ShopcartExpandableListViewAdapter(groups, children, this);
- selva.setCheckInterface(this);// 关键步骤1,设置复选框接口
- selva.setModifyCountInterface(this);// 关键步骤2,设置数量增减接口
- exListView.setAdapter(selva);
- for (int i = 0; i < selva.getGroupCount(); i++)
- {
- exListView.expandGroup(i);// 关键步骤3,初始化时,将ExpandableListView以展开的方式呈现
- }
- cb_check_all.setOnClickListener(this);
- tv_delete.setOnClickListener(this);
- tv_go_to_pay.setOnClickListener(this);
- }
- /**
- * 模拟数据<br>
- * 遵循适配器的数据列表填充原则,组元素被放在一个List中,对应的组元素下辖的子元素被放在Map中,<br>
- * 其键是组元素的Id(通常是一个唯一指定组元素身份的值)
- */
- private void virtualData()
- {
- for (int i = 0; i < 6; i++)
- {
- groups.add(new GroupInfo(i + "", "第八号当铺" + (i + 1) + "号店"));
- List<ProductInfo> products = new ArrayList<ProductInfo>();
- for (int j = 0; j <= i; j++)
- {
- products.add(new ProductInfo(j + "", "商品", "", groups.get(i).getName() + "的第" + (j + 1) + "个商品", 120.00 + i * j, 1));
- }
- children.put(groups.get(i).getId(), products);// 将组元素的一个唯一值,这里取Id,作为子元素List的Key
- }
- }
- @Override
- public void onClick(View v)
- {
- AlertDialog alert;
- switch (v.getId())
- {
- case R.id.all_chekbox:
- doCheckAll();
- break;
- case R.id.tv_go_to_pay:
- if (totalCount == 0)
- {
- Toast.makeText(context, "请选择要支付的商品", Toast.LENGTH_LONG).show();
- return;
- }
- alert = new AlertDialog.Builder(context).create();
- alert.setTitle("操作提示");
- alert.setMessage("总计:\n" + totalCount + "种商品\n" + totalPrice + "元");
- 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)
- {
- return;
- }
- });
- alert.show();
- break;
- case R.id.tv_delete:
- if (totalCount == 0)
- {
- Toast.makeText(context, "请选择要移除的商品", Toast.LENGTH_LONG).show();
- return;
- }
- 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)
- {
- doDelete();
- }
- });
- alert.show();
- break;
- }
- }
- /**
- * 删除操作<br>
- * 1.不要边遍历边删除,容易出现数组越界的情况<br>
- * 2.现将要删除的对象放进相应的列表容器中,待遍历完后,以removeAll的方式进行删除
- */
- protected void doDelete()
- {
- List<GroupInfo> toBeDeleteGroups = new ArrayList<GroupInfo>();// 待删除的组元素列表
- for (int i = 0; i < groups.size(); i++)
- {
- GroupInfo group = groups.get(i);
- if (group.isChoosed())
- {
- toBeDeleteGroups.add(group);
- }
- List<ProductInfo> toBeDeleteProducts = new ArrayList<ProductInfo>();// 待删除的子元素列表
- List<ProductInfo> childs = children.get(group.getId());
- for (int j = 0; j < childs.size(); j++)
- {
- if (childs.get(j).isChoosed())
- {
- toBeDeleteProducts.add(childs.get(j));
- }
- }
- childs.removeAll(toBeDeleteProducts);
- }
- groups.removeAll(toBeDeleteGroups);
- selva.notifyDataSetChanged();
- calculate();
- }
- @Override
- public void doIncrease(int groupPosition, int childPosition, View showCountView, boolean isChecked)
- {
- ProductInfo product = (ProductInfo) selva.getChild(groupPosition, childPosition);
- int currentCount = product.getCount();
- currentCount++;
- product.setCount(currentCount);
- ((TextView) showCountView).setText(currentCount + "");
- selva.notifyDataSetChanged();
- calculate();
- }
- @Override
- public void doDecrease(int groupPosition, int childPosition, View showCountView, boolean isChecked)
- {
- ProductInfo product = (ProductInfo) selva.getChild(groupPosition, childPosition);
- int currentCount = product.getCount();
- if (currentCount == 1)
- return;
- currentCount--;
- product.setCount(currentCount);
- ((TextView) showCountView).setText(currentCount + "");
- selva.notifyDataSetChanged();
- calculate();
- }
- @Override
- public void checkGroup(int groupPosition, boolean isChecked)
- {
- GroupInfo group = groups.get(groupPosition);
- List<ProductInfo> childs = children.get(group.getId());
- for (int i = 0; i < childs.size(); i++)
- {
- childs.get(i).setChoosed(isChecked);
- }
- if (isAllCheck())
- cb_check_all.setChecked(true);
- else
- cb_check_all.setChecked(false);
- selva.notifyDataSetChanged();
- calculate();
- }
- @Override
- public void checkChild(int groupPosition, int childPosiTion, boolean isChecked)
- {
- boolean allChildSameState = true;// 判断改组下面的所有子元素是否是同一种状态
- GroupInfo group = groups.get(groupPosition);
- List<ProductInfo> childs = children.get(group.getId());
- for (int i = 0; i < childs.size(); i++)
- {
- if (childs.get(i).isChoosed() != isChecked)
- {
- allChildSameState = false;
- break;
- }
- }
- if (allChildSameState)
- {
- group.setChoosed(isChecked);// 如果所有子元素状态相同,那么对应的组元素被设为这种统一状态
- } else
- {
- group.setChoosed(false);// 否则,组元素一律设置为未选中状态
- }
- if (isAllCheck())
- cb_check_all.setChecked(true);
- else
- cb_check_all.setChecked(false);
- selva.notifyDataSetChanged();
- calculate();
- }
- private boolean isAllCheck()
- {
- for (GroupInfo group : groups)
- {
- if (!group.isChoosed())
- return false;
- }
- return true;
- }
- /** 全选与反选 */
- private void doCheckAll()
- {
- for (int i = 0; i < groups.size(); i++)
- {
- groups.get(i).setChoosed(cb_check_all.isChecked());
- GroupInfo group = groups.get(i);
- List<ProductInfo> childs = children.get(group.getId());
- for (int j = 0; j < childs.size(); j++)
- {
- childs.get(j).setChoosed(cb_check_all.isChecked());
- }
- }
- selva.notifyDataSetChanged();
- }
- /**
- * 统计操作<br>
- * 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<br>
- * 3.给底部的textView进行数据填充
- */
- private void calculate()
- {
- totalCount = 0;
- totalPrice = 0.00;
- for (int i = 0; i < groups.size(); i++)
- {
- GroupInfo group = groups.get(i);
- List<ProductInfo> childs = children.get(group.getId());
- for (int j = 0; j < childs.size(); j++)
- {
- ProductInfo product = childs.get(j);
- if (product.isChoosed())
- {
- totalCount++;
- totalPrice += product.getPrice() * product.getCount();
- }
- }
- }
- tv_total_price.setText("¥" + totalPrice);
- tv_go_to_pay.setText("去支付(" + totalCount + ")");
- }
- }