I am using tab layout in my activity which has two tabs. When i switch to another tab current tab fragment is destroyed, and another tab is created from scratch ( from Oncreate() lifecycle method) hoverver I went once before.

private void Tablayout_TabSelected(object sender, TabSelectedEventArgs e)
    {
        Tab tab = e.Tab;
        if (tab.Position == 0)
        {
            SupportFragmentManager.BeginTransaction().Replace(Resource.Id.fragmentContainerView, listFrag ??= new MusicListFragment(), "ListFrag").Commit();
        }
        else if (tab.Position == 1)
        {
            SupportFragmentManager.BeginTransaction().Replace(Resource.Id.fragmentContainerView, favFrag ??= new FavoriteSongsFragment(), "FavFrag").Commit();
        }
    }

is, isn't it a good idea to keep the whole fragment in memory instead of creating a new one every time?

Or How can i improve my switching ?

CodePudding user response：

Try this

Use FragmentPagerAdapter it is easy and work well method

1. Create class extend FragmentPagerAdapter

2. follow the below code in your adapter

   public class FragmentAdapter extends FragmentPagerAdapter {
       Context context;
       int totalTaps;
   
     public FragmentAdapter(@NonNull FragmentManager fm, Context context, int totalTaps) {
       super(fm);
       this.context = context;
       this.totalTaps = totalTaps;
   }
   
   @NonNull
   @Override
   public Fragment getItem(int position) {
   
       switch (position){
           case 0:
               MusicListFragment musicListFragment= new MusicListFragment();
               return musicListFragment;
           case 1:
               FavoriteSongsFragment favoriteSongsFragment= new FavoriteSongsFragment();
               return favoriteSongsFragment;
   
           default:
               return null;
       }
   }
   
    @Override
    public int getCount() {
       return totalTaps;
     }
   }
   

MainActivity

public class HomePage extends AppCompatActivity {

ViewPager viewPager;
TabLayout tabLayout;
FragmentAdapter adapter;

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_home_page);
    viewPager = findViewById(R.id.viewPager);
    tabLayout = findViewById(R.id.tabLayout);
    adapter = new FragmentAdapter(getSupportFragmentManager(),getApplicationContext(),2);

    tabLayout.addTab(tabLayout.newTab().setText("ListFrag"));
    tabLayout.addTab(tabLayout.newTab().setText("FavFrag"));

     viewPager.addOnPageChangeListener(new TabLayout.TabLayoutOnPageChangeListener(tabLayout));
     tabLayout.addOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
         @Override
         public void onTabSelected(TabLayout.Tab tab) {
             viewPager.setCurrentItem(tab.getPosition());
         }

         @Override
         public void onTabUnselected(TabLayout.Tab tab) {

         }

         @Override
         public void onTabReselected(TabLayout.Tab tab) {

         }
     });
     viewPager.setAdapter(adapter);
}