public class MainActivity extends AppCompatActivity { private List<Fruit> fruitList = new ArrayList<Fruit>(); //先定义一个list @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); //设定在哪个view呈现 initFruits(); // 初始化水果数据 FruitAdapter adapter = new FruitAdapter(MainActivity.this, R.layout.fruit_item, fruitList); //自定义适配器搭配listview使用 第一个参数:传给谁 第二个参数:谁传的 第三个参数要传啥 ListView listView = (ListView) findViewById(R.id.listview); listView.setAdapter(adapter); // setAdapter专门用于传进去 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); }}}
//先写一支class用来初始化 上面有用到
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; }}
//自定义适配器
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); // Fruit位置 View view; ViewHolder viewHolder; if (convertView == null) { view = LayoutInflater.from(getContext()).inflate(resourceId, parent, false); viewHolder = new ViewHolder();//优化性能用的 viewHolder.fruitImage = (ImageView) view.findViewById (R.id.fruit_image); viewHolder.fruitName = (TextView) view.findViewById (R.id.fruit_name); view.setTag(viewHolder); //存View } else { view = convertView; viewHolder = (ViewHolder) view.getTag(); //取ViewHolder } viewHolder.fruitImage.setImageResource(fruit.getImageId()); viewHolder.fruitName.setText(fruit.getName()); return view; } class ViewHolder { ImageView fruitImage; TextView fruitName; }}