《Android移动应用基础教程》之Android购物商城

activity_main.xml代码如下：

<?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">
    <TextView
        android:layout_width="match_parent"
        android:layout_height="45dp"
        android:text="购物商城"
        android:textSize="18sp"
        android:textColor="#FFFFFF"
        android:background="#FF8F03"
        android:gravity="center"/>
    <ListView
        android:id="@+id/lv"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"/>
</LinearLayout>

list_item.xml代码如下：

<?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="match_parent"
    android:padding="16dp">

    <ImageView
        android:id="@+id/iv"
        android:layout_width="120dp"
        android:layout_height="90dp"
        android:layout_centerVertical="true" />

    <RelativeLayout
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_centerVertical="true"
        android:layout_marginLeft="10dp"
        android:layout_toRightOf="@+id/iv">

        <TextView
            android:id="@+id/title"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="桌子"
            android:textColor="#000000"
            android:textSize="20sp" />

        <TextView
            android:id="@+id/tv_price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/title"
            android:layout_marginTop="10dp"
            android:text="价格："
            android:textColor="#FF8F03"
            android:textSize="20sp" />

        <TextView
            android:id="@+id/price"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:layout_below="@+id/title"
            android:layout_marginTop="10dp"
            android:layout_toRightOf="@+id/tv_price"
            android:text="1000"
            android:textColor="#FF8F03"
            android:textSize="20sp" />
    </RelativeLayout>
</RelativeLayout>

MainActivity.java代码如下：

package com.itcast.listview;

import android.app.Activity;
import android.os.Bundle;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.ListView;
import android.widget.TextView;
public class MainActivity extends Activity {
    private ListView mListView;
    //需要适配的数据
    private String[] titles = { "桌子", "苹果", "蛋糕", "线衣", "猕猴桃",
            "围巾"};
    private String[] prices = { "1800元", "10元/kg", "300元", "350元", "10元/kg",
            "280元"};
    //图片集合
    private int[] icons = {R.drawable.table,R.drawable.apple,R.drawable.cake,
            R.drawable.wireclothes,R.drawable.kiwifruit,R.drawable.scarf};
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        //初始化ListView控件
        mListView = (ListView) findViewById(R.id.lv);
        //创建一个Adapter的实例
        MyBaseAdapter mAdapter = new MyBaseAdapter();
        //设置Adapter
        mListView.setAdapter(mAdapter);
    }
    //创建一个类继承BaseAdapter
    class MyBaseAdapter extends BaseAdapter {
        //得到item的总数
        @Override
        public int getCount() {
            //返回ListView Item条目的总数
            return titles.length;
        }
        //得到Item代表的对象
        @Override
        public Object getItem(int position) {
            //返回ListView Item条目代表的对象
            return titles[position];
        }
        //得到Item的id
        @Override
        public long getItemId(int position) {
            //返回ListView Item的id
            return position;
        }
        //得到Item的View视图
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
         /*   //将list_item.xml文件找出来并转换成View对象
            View view  = View.inflate(MainActivity.this,
                    R.layout.list_item, null);
            //找到list_item.xml中创建的TextView
            TextView title = (TextView) view.findViewById(R.id.title);
            TextView price = (TextView) view.findViewById(R.id.price);
            ImageView iv = (ImageView) view.findViewById(R.id.iv);
            title.setText(titles[position]);
            price.setText(prices[position]);
            iv.setBackgroundResource(icons[position]);
            return view;*/
            ViewHolder holder = null;
            if(convertView == null){
                //将list_item.xml文件找出来并转换成View对象
                convertView  = View.inflate(MainActivity.this, R.layout.list_item, null);
                //找到list_item.xml中创建的TextView
                holder = new ViewHolder();
                holder.title = (TextView) convertView.findViewById(R.id.title);
                holder.price = (TextView) convertView.findViewById(R.id.price);
                holder.iv = (ImageView) convertView.findViewById(R.id.iv);
                convertView.setTag(holder);
            }else{
                holder = (ViewHolder) convertView.getTag();
            }
            holder.title.setText(titles[position]);
            holder.price.setText(prices[position]);
            holder.iv.setBackgroundResource(icons[position]);
            return convertView;



        }

    }
    static class ViewHolder{
        TextView title;
        TextView price;
        ImageView iv;
    }
}

实现效果如下：