ListView适配器:缓存视图

public class MyAdapter extends BaseAdapter {
    private Context context;
    private List<String> data;

    public MyAdapter(Context context, List<String> data) {
        this.context = context;
        this.data = data;
    }

    @Override
    public int getCount() {
        return data.size();
    }

    @Override
    public Object getItem(int position) {
        return data.get(position);
    }

    @Override
    public long getItemId(int position) {
        return position;
    }

    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        ViewHolder viewHolder;

        if (convertView == null) {
            // 如果没有可重用的视图，则创建一个新的视图
            convertView = LayoutInflater.from(context).inflate(R.layout.list_item, parent, false);
            viewHolder = new ViewHolder();
            viewHolder.textView = convertView.findViewById(R.id.text_view);
            convertView.setTag(viewHolder);
        } else {
            // 如果有可重用的视图，则直接使用它
            viewHolder = (ViewHolder) convertView.getTag();
        }

        // 设置数据
        viewHolder.textView.setText(data.get(position));

        return convertView;
    }

    // ViewHolder类用于缓存视图
    private static class ViewHolder {
        TextView textView;
    }
}

<?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="wrap_content"
    android:orientation="vertical"
    android:padding="16dp">

    <TextView
        android:id="@+id/text_view"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:textSize="16sp" />

</LinearLayout>

public class MainActivity extends AppCompatActivity {
    private ListView listView;
    private MyAdapter adapter;
    private List<String> data;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        listView = findViewById(R.id.list_view);
        data = new ArrayList<>();
        for (int i = 1; i <= 100; i++) {
            data.add("Item " + i);
        }

        adapter = new MyAdapter(this, data);
        listView.setAdapter(adapter);
    }
}

<?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">

    <ListView
        android:id="@+id/list_view"
        android:layout_width="match_parent"
        android:layout_height="match_parent" />

</LinearLayout>