一、比起上次ListView的简单例子，这个例子相对要复杂，首先上图
每一个列表项由两部分组成：一个ImageView，一个TextView。首先为列表项生成一个类：
1 package com.matclone.ListViewTest; 2 3 public class Country { 4 private int imageId; 5 private String name; 6 7 public Country(int imageId, String name) { 8 super(); 9 this.imageId = imageId; 10 this.name = name; 11 } 12 13 public int getImageId() { 14 return imageId; 15 } 16 17 public String getName() { 18 return name; 19 } 20 21 }
二、上例已经了解了构建一个ListView需要的条件有
首先解决数据来源问题，每一个子项的图片都在res/drawable/文件夹中：
1 private List<Country> countryList = new ArrayList<Country>(); 2 3 private void createList() { 4 countryList.add(new Country(R.drawable.flag_belgium, "比利时")); 5 countryList.add(new Country(R.drawable.flag_canada, "加拿大")); 6 countryList.add(new Country(R.drawable.flag_europe, "欧盟")); 7 countryList.add(new Country(R.drawable.flag_france, "法国")); 8 countryList.add(new Country(R.drawable.flag_greece, "希腊")); 9 countryList.add(new Country(R.drawable.flag_ireland, "爱尔兰")); 10 countryList.add(new Country(R.drawable.flag_italy, "意大利")); 11 countryList.add(new Country(R.drawable.flag_romania, "罗马利亚")); 12 countryList.add(new Country(R.drawable.flag_uk, "英国")); 13 countryList.add(new Country(R.drawable.flag_usa, "美国")); 14 }
然后是ListView中子项的布局，也就是V层，新建布局文件：
1 <?xml version="1.0" encoding="utf-8"?> 2 <LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" 3 android:layout_width="match_parent" 4 android:layout_height="match_parent" > 5 6 <ImageView 7 android:id="@+id/countryImage" 8 android:layout_width="33dp" 9 android:layout_height="33dp" 10 /> 11 12 <TextView 13 android:id="@+id/countryName" 14 android:layout_width="wrap_content" 15 android:layout_height="wrap_content" 16 android:layout_gravity="center_vertical" 17 android:layout_marginLeft="10dp" 18 /> 19 20 </LinearLayout>
接下来是适配器，即C层，需要做以下几件事：
public class CountryAdapter extends ArrayAdapter<Country>
重写ArrayAdapter类的getView()方法，在这个方法中，我们需要做以下几件事：
1 package com.matclone.ListViewTest; 2 3 import java.util.List; 4 5 import android.content.Context; 6 import android.view.LayoutInflater; 7 import android.view.View; 8 import android.view.ViewGroup; 9 import android.widget.ArrayAdapter; 10 import android.widget.ImageView; 11 import android.widget.TextView; 12 13 public class CountryAdapter extends ArrayAdapter<Country> { 14 private int layoutFileId; 15 16 public CountryAdapter(Context context, int textViewResourceId, List<Country> objects) { 17 super(context, textViewResourceId, objects); 18 // TODO Auto-generated constructor stub 19 this.layoutFileId = textViewResourceId; 20 } 21 22 @Override 23 public View getView(int position, View convertView, ViewGroup parent) { 24 // TODO Auto-generated method stub 25 Country country = getItem(position); 26 View view; 27 ViewHolder viewHolder; 28 29 if (convertView == null) { 30 view = LayoutInflater.from(getContext()).inflate(layoutFileId, null); 31 viewHolder = new ViewHolder(); 32 33 viewHolder.countryImage = (ImageView) view.findViewById(R.id.countryImage); 34 viewHolder.countryName = (TextView) view.findViewById(R.id.countryName); 35 view.setTag(viewHolder); 36 } else { 37 view = convertView; 38 viewHolder = (ViewHolder) view.getTag(); 39 } 40 41 viewHolder.countryImage.setImageResource(country.getImageId()); 42 viewHolder.countryName.setText(country.getName()); 43 44 return view; 45 } 46 47 /* ViewHolder用于对控件的实例进行缓存，优化性能 48 * 1. convertView==null, 创建ViewHolder对象，并将控件的实例存放进来 49 * 然后通过View.setTag()方法将ViewHolder对象存储在View中 50 * 2. convertView!=null， 调用View.getTag()方法，将ViewHolder对象重新取出 51 */ 52 class ViewHolder { 53 ImageView countryImage; 54 TextView countryName; 55 } 56 }
在活动中使用继承的适配器，并为ListView的子项添加点击事件监听器
1 package com.matclone.ListViewTest; 2 3 import java.util.ArrayList; 4 import java.util.List; 5 6 import android.content.Context; 7 import android.content.Intent; 8 import android.os.Bundle; 9 import android.view.View; 10 import android.widget.AdapterView; 11 import android.widget.Toast; 12 import android.widget.AdapterView.OnItemClickListener; 13 import android.widget.ListView; 14 15 public class ListViewStyle2 extends BaseActivity { 16 private List<Country> countryList = new ArrayList<Country>(); 17 18 @Override 19 protected void onCreate(Bundle savedInstanceState) { 20 // TODO Auto-generated method stub 21 super.onCreate(savedInstanceState); 22 this.setContentView(R.layout.listview_style2); 23 24 createList(); 25 CountryAdapter adapter = new CountryAdapter(ListViewStyle2.this, R.layout.country_item, countryList); 26 ListView lvStyle2 = (ListView) this.findViewById(R.id.lvStyle2); 27 lvStyle2.setAdapter(adapter); 28 lvStyle2.setOnItemClickListener(new OnItemClickListener() { 29 @Override 30 public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 31 // TODO Auto-generated method stub 32 Country country = countryList.get(position); 33 Toast.makeText(ListViewStyle2.this, country.getName(), Toast.LENGTH_SHORT).show(); 34 } 35 }); 36 } 37 38 private void createList() { 39 countryList.add(new Country(R.drawable.flag_belgium, "比利时")); 40 countryList.add(new Country(R.drawable.flag_canada, "加拿大")); 41 countryList.add(new Country(R.drawable.flag_europe, "欧盟")); 42 countryList.add(new Country(R.drawable.flag_france, "法国")); 43 countryList.add(new Country(R.drawable.flag_greece, "希腊")); 44 countryList.add(new Country(R.drawable.flag_ireland, "爱尔兰")); 45 countryList.add(new Country(R.drawable.flag_italy, "意大利")); 46 countryList.add(new Country(R.drawable.flag_romania, "罗马利亚")); 47 countryList.add(new Country(R.drawable.flag_uk, "英国")); 48 countryList.add(new Country(R.drawable.flag_usa, "美国")); 49 } 50 51 }
《Android第一行代码》学习记录010 - ListView用法2
原文：http://www.cnblogs.com/matclone/p/4902485.html