Android制作简单的普通购物车
本文实例为大家分享了Android普通购物车制作过程,供大家参考,具体内容如下
1.最新项目新增了类似购物车功能,如下图所示:
当时刚看到此页面的时候,第一反应是利用 ListView嵌套Listview,经过一番操作最终也实现了此功能。当时也没有考虑性能问题,只考虑能写出来。后来嵌套数据,当数据量较大时,滑动Listview可以明显感觉到卡顿,这对用户来说是很难忍受的,所以才有了找到替代方案的想法,看到网上主流的是用ExpandableListView来实现此功能,所以我也用此方案来写一下。
2.成型后的Demo,如下图所示:
3.思路:
1).选用ExpandableListView作为控件
2).给每个数据源添加一个选中标志,isChecked,根据ischecked,控制checkbox的状态;
ExpandableListView相关普及
#1.首先看下ExpandableListView的adapter,与普通的ListView adapter不同
public class MyExpandAdapter extends BaseExpandableListAdapter { //红色部分的数据源 List<OrderDetailsEntity> group_head = new ArrayList(); //内层部分数据源 List<List<ProductDetails>> child = new ArrayList(); Context context; LayoutInflater inflater; public MyExpandAdapter(Context content) { // 初始化组、子列表项 group_head = new ArrayList<OrderDetailsEntity>(); child = new ArrayList<List<ProductDetails>>(); inflater = LayoutInflater.from(context); } public MyExpandAdapter(Context context, List<OrderDetailsEntity> group_head, List<List<ProductDetails>> child) { this.context = context; // 初始化组、子列表项 this.group_head = group_head; this.child = child; inflater = LayoutInflater.from(context); } /****************************跟普通adapter一样******************************/ @Override public int getGroupCount() { return this.group_head.size(); } @Override public int getChildrenCount(int position) { if (position < 0 || position >= this.child.size()) return 0; return child.get(position).size(); } @Override public OrderDetailsEntity getGroup(int groupPosition) { return group_head.get(groupPosition); } @Override public ProductDetails getChild(int groupPosition, int childPosition) { return child.get(groupPosition).get(childPosition); } @Override public long getGroupId(int groupPosition) { return groupPosition; } @Override public long getChildId(int groupPosition, int childPosition) { return childPosition; } /**************************************************************************/ @Override public boolean hasStableIds() { //分组和子选项是否持有稳定的ID, 就是说底层数据的改变会不会影响到它们 return true; } private boolean isSelectAll(OrderDetailsEntity entity) { int count = 0; for (ProductDetails p : entity.getProductDetails()) { if (p.isChecked()) { count++; } } return entity.getProductDetails().size() == count; } /*************************与普通adapter的getView方法一样**********************/ @Override public View getGroupView(int groupPosition, boolean isExpanded, View convertView, ViewGroup parent) { ViewHolderGroup group; if (convertView == null) { convertView = inflater.inflate(R.layout.item, parent, false); group = new ViewHolderGroup(); group.cb_all = (CheckBox) convertView.findViewById(R.id.cb_checkAll); group.tv_name = (TextView) convertView.findViewById(R.id.tv_name); convertView.setTag(group); } else { group = (ViewHolderGroup) convertView.getTag(); } group.tv_name.setText( group_head.get(groupPosition).getMemberId() + "," + group_head.get(groupPosition).getShopName()); group.cb_all.setChecked(isSelectAll(getGroup(groupPosition))); return convertView; } @Override public View getChildView(int groupPosition, int childPosition, boolean isLastChild, View convertView, ViewGroup parent) { ViewHolderChild childV; if (convertView == null) { convertView = inflater.inflate(R.layout.item_inner, parent, false); childV = new ViewHolderChild(); childV.cb = (CheckBox) convertView.findViewById(R.id.cb_check); childV.iv = (ImageView) convertView.findViewById(R.id.iv_img); childV.name = (TextView) convertView.findViewById(R.id.name); convertView.setTag(childV); } else { childV = (ViewHolderChild) convertView.getTag(); } childV.name.setText(getChild(groupPosition, childPosition).getProductName()); childV.cb.setChecked(getChild(groupPosition, childPosition).isChecked()); return convertView; } /****************************************************************************/ @Override public boolean isChildSelectable(int groupPosition, int childPosition) { //// 指定位置的子视图是否可选择。 // 调用Activity里的ChildSelect方法 // Toast.makeText(context, "gp="+groupPosition+",cp="+childPosition, // Toast.LENGTH_LONG).show(); return true; } static class ViewHolderGroup { CheckBox cb_all; TextView tv_name; } static class ViewHolderChild { CheckBox cb; ImageView iv; TextView name; } }
#2.ExpandableListView 展开
for (int i = 0; i < adapter.getGroupCount(); i++) { sp_date_list.expandGroup(i); }
3).ExpandableListView 去掉默认图标
sp_date_list.setGroupIndicator(null);
4).ExpandableListView itemClick事件处理
1. setOnChildClickListener
2. setOnGroupClickListener
3. setOnGroupCollapseListener
4. setOnGroupExpandListener
通过方法名我们就能知道各自的用途,它们分别设置单击子选项、单击分组项、分组合并、分组展开的监听器。
// 设置分组项的点击监听事件 expandableListView.setOnGroupClickListener(new ExpandableListView.OnGroupClickListener() { @Override public boolean onGroupClick(ExpandableListView expandableListView, View view, int i, long l) { Toast.makeText(getApplicationContext(), groupStrings[i], Toast.LENGTH_SHORT).show(); //如果处理事件,return true,默认return false return false; } // 设置子选项点击监听事件 expandableListView.setOnChildClickListener(new ExpandableListView.OnChildClickListener() { @Override public boolean onChildClick(ExpandableListView parent, View v, int groupPosition, int childPosition, long id) { Toast.makeText(getApplicationContext(), childStrings[groupPosition][childPosition], Toast.LENGTHshow(); return true; } });
以上就是本文的全部内容,希望对大家的学习有所帮助,也希望大家多多支持我们。