类似于iOS的UITableView
定义一个实体类,作为ListView的适配器的适配类型。其中name为水果名称、imageId为水果的图片(图片资源可以随便弄几个占用)
public class Fruit {
private String name;
private int imageId;
public Fruit(String name, int imageId) { this.name = name; this.imageId = imageId; }
public String getName() { return name; }
public int getImageId() { return imageId; }
}
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为ListView自定义布局
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android" android:orientation="horizontal" android:layout_width="match_parent" android:layout_height="match_parent">
<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_vertical" android:layout_marginLeft="10dp" />
</LinearLayout>
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自定义适配器,继承自ArrayAdapter(最终提升了ListView的运行效率:convertView的重用、避免多次findViewById)
public class FruitAdapter extends ArrayAdapter<Fruit> {
private int resourceId;
public FruitAdapter(Context context, int textViewResourceId, List<Fruit> objects) { super(context, textViewResourceId, objects); resourceId = textViewResourceId; }
@Override public View getView(int position, View convertView, ViewGroup parent) { Fruit fruit = getItem(position); // 获取当前项的Fruit实例 View view; ViewHolder viewHolder; if (convertView == null) { view = LayoutInflater.from(getContext()).inflate(resourceId, parent, false); viewHolder = new ViewHolder(); viewHolder.fruitImage = (ImageView) view.findViewById (R.id.fruit_image); viewHolder.fruitName = (TextView) view.findViewById (R.id.fruit_name); view.setTag(viewHolder); // 将ViewHolder存储在View中 } else { view = convertView; viewHolder = (ViewHolder) view.getTag(); // 重新获取ViewHolder } viewHolder.fruitImage.setImageResource(fruit.getImageId()); viewHolder.fruitName.setText(fruit.getName()); return view; }
class ViewHolder {
ImageView fruitImage;
TextView fruitName;
}
}
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修改MainActivity,设置ListView,选中某行弹出水果名称
public class MainActivity extends AppCompatActivity {
private List<Fruit> fruitList = new ArrayList<Fruit>();
@Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); initFruits(); // 初始化水果数据 FruitAdapter adapter = new FruitAdapter(MainActivity.this, R.layout.fruit_item, fruitList); ListView listView = (ListView) findViewById(R.id.list_view); listView.setAdapter(adapter); listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { @Override public void onItemClick(AdapterView<?> parent, View view, int position, long id) { Fruit fruit = fruitList.get(position); Toast.makeText(MainActivity.this, fruit.getName(), Toast.LENGTH_SHORT).show(); } }); }
private void initFruits() { for (int i = 0; i < 2; i++) { 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); } }
}
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运行结果
![](https://images2018.cnblogs.com/blog/750223/201805/750223-20180508091240022-1510037256.png)
参考:《第一行代码》第二版