在安卓的数据列表显示的时候,通常会用到ListView,所以列出下学习时候遇到的
1,用系统自定义的ListView
首先在xml文件中建立listview
<ListView
android:id="@+id/list_view"
android:layout_width="match_parent"
android:layout_height="match_parent"
></ListView>然后在MainAvtivity中建立数据,此时的数据一般都是提前准备好的,一般是网上下载的或者从数据库中提取的
private String[] data = { "Apple" , "Banana" , "Orange" , "Watermelon",
"Pear", "Grape", "Pineapple", "Strawberry", "Cherry", "Mango" };
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate( savedInstanceState);
requestWindowFeature(Window. FEATURE_NO_TITLE);
setContentView(R.layout. activity_main);
ArrayAdapter<String> adapter = new ArrayAdapter<String>(
MainActivity.this, android.R.layout.simple_list_item_1 , data );
ListView listview = (ListView) findViewById(R.id.list_view );
listview.setAdapter( adapter);
}
<ImageView
android:id="@+id/fruit_image"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
/>
<TextView
android:id="@+id/fruit_name"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_gravity="center"
android:layout_marginLeft="10dp"
/>建立一个类,继承适配器类
public class FruitAdapter extends ArrayAdapter<Fruit> {
private int resourceId ;
public FruitAdapter(Context context, int resource, List<Fruit> objects) {
super( context, resource, objects);
// TODO Auto-generated constructor stub
resourceId= resource;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
/*return super.getView(position, convertView, parent);*/
//获取当前的fruit实例
Fruit fruit= getItem( position);
View view= LayoutInflater.from(getContext()).inflate(resourceId , null);
ImageView fruitImage= (ImageView) view.findViewById(R.id. fruit_image);
TextView fruitNmae=(TextView) view.findViewById(R.id. fruit_name);
fruitImage.setImageResource( fruit.getImageId());
fruitNmae.setText( fruit.getName());
return view;
}
public class MainActivity extends Activity {
/*private String[] data = { "Apple", "Banana", "Orange", "Watermelon",
"Pear", "Grape", "Pineapple", "Strawberry", "Cherry", "Mango" };*/
private List<Fruit> fruitList = new ArrayList<Fruit>();
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate( savedInstanceState);
/*requestWindowFeature(Window.FEATURE_NO_TITLE);*/
setContentView(R.layout. activity_main );
/*ArrayAdapter<String> adapter = new ArrayAdapter<String>(
MainActivity.this, android.R.layout.simple_list_item_1, data);
ListView listview = (ListView) findViewById(R.id.list_view);
listview.setAdapter(adapter);*/
//初始化水果
initFruit();
FruitAdapter adapter= new FruitAdapter(MainActivity. this, R.layout.fruit_item , fruitList );
ListView listView=(ListView) findViewById(R.id.list_view );
listView.setAdapter( adapter);
}
private void initFruit() {
// TODO Auto-generated method stub
Fruit apple = new Fruit( "Apple", R.drawable.apple_pic );
fruitList.add( apple);
Fruit banana = new Fruit( "Banana", R.drawable.banana_pic );
fruitList.add( banana);
Fruit orange = new Fruit( "Orange", R.drawable.orange_pic );
fruitList.add( orange);
Fruit watermelon = new Fruit( "Watermelon", R.drawable.watermelon_pic );
fruitList.add( watermelon);
Fruit pear = new Fruit( "Pear", R.drawable. pear_pic);
fruitList.add( pear);
Fruit grape = new Fruit( "Grape", R.drawable.grape_pic );
fruitList.add( grape);
Fruit pineapple = new Fruit( "Pineapple", R.drawable.pineapple_pic );
fruitList.add( pineapple);
Fruit strawberry = new Fruit( "Strawberry", R.drawable.strawberry_pic );
fruitList.add( strawberry);
Fruit cherry = new Fruit( "Cherry", R.drawable.cherry_pic );
fruitList.add( cherry);
Fruit mango = new Fruit( "Mango", R.drawable.mango_pic );
fruitList.add( mango);
}
主要是listview完成初始化,然后产生一个自定义的适配器进行装配数据,传给ListView
public class FruitAdapter extends ArrayAdapter<Fruit> {
private int resourceId;
public FruitAdapter(Context context, int resource, List<Fruit> objects) {
super(context, resource, objects);
// TODO Auto-generated constructor stub
resourceId=resource;
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
// TODO Auto-generated method stub
/*return super.getView(position, convertView, parent);*/
//获取当前的fruit实例
Fruit fruit= getItem(position);
/*
* convertView主要是将之前加载好的布局进行缓存
*/
View view;
ViewHolder viewHolder;
if(convertView==null)
{
view= LayoutInflater.from(getContext()).inflate(resourceId, null);
viewHolder=new ViewHolder();
viewHolder.fruitImage=(ImageView) view.findViewById(R.id.fruit_image);
viewHolder.fruitName=(TextView) view.findViewById(R.id.fruit_name);
}
else
{
view =convertView;
viewHolder=(ViewHolder) view.getTag();
}
/* ImageView fruitImage= (ImageView) view.findViewById(R.id.fruit_image);
TextView fruitNmae=(TextView) view.findViewById(R.id.fruit_name);
fruitImage.setImageResource(fruit.getImageId());
fruitNmae.setText(fruit.getName());*/
viewHolder.fruitImage.setImageResource(fruit.getImageId());
viewHolder.fruitName.setText(fruit.getName());
return view;
}
class ViewHolder{
ImageView fruitImage;
TextView fruitName;
}
}
原文:http://blog.csdn.net/hll174/article/details/45601759