适配器未设置为listview android

// 创建适配器类
public class MyAdapter extends BaseAdapter {
    private List<String> data; // 数据源

    public MyAdapter(List<String> data) {
        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) {
        // 创建或复用View，并设置数据项的显示方式
        if (convertView == null) {
            convertView = LayoutInflater.from(parent.getContext()).inflate(android.R.layout.simple_list_item_1, parent, false);
        }
        TextView textView = convertView.findViewById(android.R.id.text1);
        textView.setText(data.get(position));
        return convertView;
    }
}

// 在Activity或Fragment中使用适配器
public class MyActivity extends AppCompatActivity {
    private ListView listView;

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

        listView = findViewById(R.id.list_view);

        List<String> data = new ArrayList<>();
        data.add("Item 1");
        data.add("Item 2");
        data.add("Item 3");

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