public View onCreateView (LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)

public class DemoFragment extends Fragment {
    public static DemoFragment newInstance(String someTitle) {
        DemoFragment demoFragment = new DemoFragment();
        args.putString("someTitle", someTitle);
        demoFragment.setArguments(args);
        return demoFragment;
    }
    
    ...
}

public class DemoFragment extends Fragment {
    ... 
    
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
       // Get arguments
       String someTitle = getArguments().getString("someTitle", "");
    }
    
    ...
}

DemoFragment.newInstance("测试").show(getSupportFragmentManager(), "DemoFragment");

((MainActivity) getActivity()).doPositiveClick();

public class NewsItemFragment extends Fragment {
    OnNewsItemSelectedListener mCallback;

    // Container Activity must implement this interface
    public interface OnNewsItemSelectedListener {
        public void onNewsItemSelected(int position);
    }
    
    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        
        // This makes sure that the container activity has implemented
        // the callback interface. If not, it throws an exception
        try {
            mCallback = (OnNewsItemSelectedListener) activity;
        } catch (ClassCastException e) {
            throw new ClassCastException(activity.toString()
                    + " must implement OnNewsItemSelectedListener");
        }
    }
    
    ...
}

Override
public void onListItemClick(ListView l, View v, int position, long id) {
    // Send the event to the host activity
    mCallback.onNewsItemSelected(position);
}

public class MainActivity extends AppCompatActivity implements NewsItemFragment.OnNewsItemSelectedListener
{
    ...
    
    @Override
    public void onNewsItemSelected(int position)
    {
        //Do something with the position value passed back
        Toast.makeText(activity, "Clicked "+ position, Toast.LENGTH_LONG).show();
        
    }
}