可以通过使用接口在Activity和Fragment之间进行通信和数据共享。以下是示例代码：

1. 创建一个接口

public interface MyListener {
    void onDataReceived(String data);
}

2. 在Activity中实现接口，并在Fragment中向Activity注册接口

public class MainActivity extends AppCompatActivity implements MyListener {

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

        MyFragment fragment = new MyFragment();
        fragment.setListener(this); // 注册接口

        getSupportFragmentManager().beginTransaction()
                .replace(R.id.container, fragment)
                .commit();
    }

    @Override
    public void onDataReceived(String data) {
        // 从Fragment接收数据
        Log.d("MainActivity", "Received data: " + data);
    }
}

3. 在Fragment中调用接口方法，向Activity发送数据

public class MyFragment extends Fragment {
    private MyListener mListener;

    public void setListener(MyListener listener) {
        mListener = listener;
    }

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        if (context instanceof MyListener) {
            mListener = (MyListener) context;
        } else {
            throw new RuntimeException(context.toString()
                    + " must implement MyListener");
        }
    }

    @Override
    public void onDetach() {
        super.onDetach();
        mListener = null;
    }

    private void sendDataToActivity(String data) {
        if (mListener != null) {
            mListener.onDataReceived(data);
        }
    }
}