如何使用 RecyclerView 更新片段数据？

Question

I have a ViewPager with 12 fragments . I need to get data from API and update the fragments when scrolling. How do I update the contents of fragment, with only one fragment updating for 12 pages?

My fragment layout fragment_item:

<ScrollView xmlns:android="http://schemas.android.com/apk/res/android"
xmlns:app="http://schemas.android.com/apk/res-auto"
android:id="@+id/content"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:background="@color/surface">

<LinearLayout
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:layout_marginEnd="20dp"
    android:layout_marginStart="20dp"
    android:orientation="vertical">


    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/khaire"
        android:gravity="center"
        android:text="Overal Working Hour"
        android:textColor="@color/colorPrimary"
        android:textSize="20sp"
        android:textStyle="bold" />

    <TextView
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:background="@color/colorPrimary"
        android:gravity="center"
        android:padding="15dp"
        android:text="January"
        android:textColor="@color/white"
        android:textSize="20sp"
        android:textStyle="bold" />    

My main activity code:

public class MainActivity extends AppCompatActivity {

private static final int num_pages = 12;
private ViewPager mPager;
private PagerAdapter mPagerAdapter;

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);  
    mPager = findViewById(R.id.pager);
    mPagerAdapter = new ScreenAdapter(getSupportFragmentManager());
    mPager.setAdapter(mPagerAdapter);
  private class ScreenAdapter extends FragmentStatePagerAdapter {
 public ScreenAdapter(FragmentManager fm) {
        super(fm);
    }

    @Override
    public Fragment getItem(int i) {
        return new SliderFragment();
    }

    @Override
    public int getCount() {
        return num_pages;
    }
}

My SlideFragment class:

public class SliderFragment extends Fragment {

Toolbar toolbar;


@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    ViewGroup rootView = (ViewGroup) inflater.inflate(R.layout.fragment_item,container,false);
    return rootView;
}

Now I want to have same fragment while scrolling the page but with diff texts how could I do that... And if possible use RecyclerView also.

Answer 1

You could create a new Class (UpdatingFragment) with public abstract updateView(); that extends Fragment.

Create your SliderFragment by extending UpdatingFragment instead of Fragment

In the SliderFragment in onCreateView() at the end call updateView() .

Write an overwrite method in your SliderFragment for what you need to update (anything you want to show on the UI)

Adjust your screenAdapter to return and take UpdatingFragment 's instead of Fragments.

Now whenever your fragments onCreateView gets called all their UI data gets updated, and if you create a list of SliderFragments and pass that into your adapter instead of creating new ones, you can just run a for loop over that list and call updateView() for each fragment.