将数据从DialogFragment返回到调用活动

public class MyDialogFragment extends DialogFragment {
    // 定义接口
    public interface OnDataSelectedListener {
        void onDataSelected(String data);
    }

    private OnDataSelectedListener mListener;

    @Override
    public void onAttach(Context context) {
        super.onAttach(context);
        try {
            mListener = (OnDataSelectedListener) context;
        } catch (ClassCastException e) {
            throw new ClassCastException(context.toString() + " must implement OnDataSelectedListener");
        }
    }

    // 在需要返回数据的地方调用接口方法
    private void sendData(String data) {
        mListener.onDataSelected(data);
    }
}

public class MainActivity extends AppCompatActivity implements MyDialogFragment.OnDataSelectedListener {
    // ...

    @Override
    public void onDataSelected(String data) {
        // 处理返回的数据
        Log.d("MainActivity", "Selected data: " + data);
    }
}

public class MyFragment extends Fragment {
    // ...

    private void showDialogFragment() {
        MyDialogFragment dialogFragment = new MyDialogFragment();
        dialogFragment.setTargetFragment(this, 1);
        dialogFragment.show(getFragmentManager(), "dialog");
    }

    @Override
    public void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if (requestCode == 1 && resultCode == Activity.RESULT_OK) {
            String result = data.getStringExtra("data");
            // 处理返回的数据
            Log.d("MyFragment", "Selected data: " + result);
        }
    }
}

public class MyDialogFragment extends DialogFragment {
    // ...

    private void sendData(String data) {
        Intent intent = new Intent();
        intent.putExtra("data", data);
        getTargetFragment().onActivityResult(getTargetRequestCode(), Activity.RESULT_OK, intent);
    }
}

public class MyDialogFragment extends DialogFragment {
    // ...

    private void sendData(String data) {
        MyViewModel viewModel = new ViewModelProvider(requireActivity()).get(MyViewModel.class);
        viewModel.setData(data);
    }
}

public class MainActivity extends AppCompatActivity {
    // ...

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        // ...

        MyViewModel viewModel = new ViewModelProvider(this).get(MyViewModel.class);
        viewModel.getData().observe(this, new Observer<String>() {
            @Override
            public void onChanged(String data) {
                // 处理返回的数据
                Log.d("MainActivity", "Selected data: " + data);
            }
        });
    }
}