从Activity访问片段的TextView (在viewpager中)

<TextView
    android:id="@+id/fragmentTextView"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="Hello Fragment!" />

public class MyFragment extends Fragment {
    private TextView fragmentTextView;

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_layout, container, false);
        fragmentTextView = view.findViewById(R.id.fragmentTextView);
        return view;
    }

    public TextView getFragmentTextView() {
        return fragmentTextView;
    }
}

public class MainActivity extends AppCompatActivity {
    private ViewPager viewPager;

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

        viewPager = findViewById(R.id.viewPager);
        MyPagerAdapter pagerAdapter = new MyPagerAdapter(getSupportFragmentManager());
        viewPager.setAdapter(pagerAdapter);

        // 获取当前显示的Fragment
        MyFragment currentFragment = (MyFragment) pagerAdapter.instantiateItem(viewPager, viewPager.getCurrentItem());
        TextView fragmentTextView = currentFragment.getFragmentTextView();

        // 在Activity中访问Fragment的TextView
        String text = fragmentTextView.getText().toString();
        Log.d("MainActivity", "Fragment TextView Text: " + text);
    }
}