android 为 ListView Item中的组件添加事件以及更新数据

短命女 2022-03-19 15:11 76阅读 0赞

// 部分代码如下：

其中holder.count 是一个EditView

holder.price 是一个TextView

@Override public View getView(final int position,View convertView,final ViewGroup parent) \{。。。。。。// 注意该方法中的Item组件不能使用holder模式，如果用该模式， 所有的组件将共享item中view的事件导致监听不到指定item中的view的事件，解决办法就是每次创建一个Item中的组件然后对于每个item 使用不同的监听事件 即 new TextWatcher() 每次都创建一个新的事件监听器final ViewHolder holder = new ViewHolder();holder.count.addTextChangedListener( new TextWatcher() \{ ..... @Override public void afterTextChanged(Editable s) \{ //holder.price 是与holder.count在同一个item的view holder.price.setText("......."); //赋值起作用 ..... //textTotalPrice是最后一个Item中的view //与holder.price 不是同一个item中的view textTotalPrice.setText("。。。。");//赋值无效 // 更新list goods.get(position).setCount(count+""); //更新数据：条用该方法的以后， 会重新执行getView方法，非局部跟新 GoodsListAdapter.this.notifyDataSetChanged();\});

完整代码如下：

import java.util.List;import org.android.util.NumberUtils;import android.app.Activity;import android.text.Editable;import android.text.TextWatcher;import android.util.Log;import android.view.LayoutInflater;import android.view.View;import android.view.ViewGroup;import android.widget.BaseAdapter;import android.widget.EditText;import android.widget.TextView;import com.mmb.shop.R;/\*\* \* 购物车:商品列表 \* \* @author wangtao \*/public class GoodsListAdapter extends BaseAdapter \{ private static List<Goods> goods; private LayoutInflater mInflater; private static TextView textTotalPrice; // private Activity context; public GoodsListAdapter(List<Goods> goods\_, Activity context) \{ goods = goods\_; mInflater = context.getLayoutInflater();// this.context = context; \} @Override public View getView(final int position,View convertView,final ViewGroup parent) \{ //最后一条显示总价 if(position == goods.size())\{ convertView = mInflater.inflate(android.R.layout.simple\_list\_item\_1, parent, false); textTotalPrice = (TextView) convertView.findViewById(android.R.id.text1); if(goods.size() > 0)\{ textTotalPrice.setText("总价: "+calcuteTotalPrice()+""); \}else\{ textTotalPrice.setText("购物车为空...."); \} return convertView; \} final ViewHolder holder = new ViewHolder(); //商品列表布局 convertView = mInflater.inflate(R.layout.list\_item\_shop\_car, parent, false); holder.id = (TextView) convertView.findViewById(R.id.goods\_id); holder.name = (TextView) convertView.findViewById(R.id.goods\_name); //不能使用Holder模式; 必须每次都创建一个不同的EditText组件 holder.count = (EditText) convertView.findViewById(R.id.goods\_count); //单价 holder.singlePrice = (TextView) convertView.findViewById(R.id.goods\_single\_price); //总价 holder.price = (TextView) convertView.findViewById(R.id.goods\_price); final Goods item = goods.get(position); //holder.id.setText(item.getId()); holder.name.setText(item.getName()); holder.count.setText(item.getCount()); holder.singlePrice.setText(item.getSinglePrice()); float totalPrice = Integer.valueOf(item.getCount()) \* Float.valueOf(item.getSinglePrice()); holder.price.setText("价格: " + totalPrice + ""); //设置没类产品的总价 goods.get(position).setTotalPrice(totalPrice + ""); //添加编辑框的change事件 holder.count.addTextChangedListener( new TextWatcher() \{ @Override public void onTextChanged(CharSequence s, int start, int before, int count) \{ \} @Override public void beforeTextChanged(CharSequence s, int start, int count, int after) \{ \} @Override public void afterTextChanged(Editable s) \{ try\{//s.toString() 即是 文本框的值 int count = Integer.valueOf(s.toString()); float singlePrice = Integer.valueOf(item.getSinglePrice()); float totalPrice = count \* singlePrice; holder.price.setText(totalPrice + ""); goods.get(position).setTotalPrice(totalPrice + ""); textTotalPrice.setText(GoodsListAdapter.calcuteTotalPrice()+""); goods.get(position).setCount(count+""); //更新数据 GoodsListAdapter.this.notifyDataSetChanged(); //View convertView = mInflater.inflate(android.R.layout.simple\_list\_item\_1, parent, false); //updateItemInTotalPrice(); \}catch(Exception e)\{ Log.e("xx", e.getStackTrace().toString()); \} \} \}); return convertView; \} // ViewHolder模式???? static class ViewHolder \{ TextView id; // ID TextView name; // 名称 EditText count; // 数量 TextView singlePrice;//单价 TextView price; // 单个商品的总价 \} /\*\* \* 计算所有购物车商品总价 \* @return \*/ private final static float calcuteTotalPrice()\{ float price = 0f; for(Goods gs : goods)\{ price += NumberUtils.toFloat(gs.getTotalPrice()); \} return price; \} //更新购物车商品总价Item ~~ 非全部整合ListView// private final void updateItemInTotalPrice()\{// TextView view = (TextView) this.getItem(goods.size());// view.setText("ddddddddd");// \} @Override public int getCount() \{ return goods.size() + 1; \} @Override public Object getItem(int position) \{ return position; \} @Override public long getItemId(int position) \{ return position; \}\}

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