Recyclerview aktualisiert Daten, aber Recyclerview scrollt mit Freezes

Question

Wenn in SettingsActivity einschalten, um nur mit Checkbox ausgewählt und meine Liste enthält in der Nähe 30 Elemente, scrollt Recyclerview normal, aber wenn ich Liste mit 900 Elemente verwenden - Recyclerview scrollt mit Freezes. Wo ist mein Weg zur Aktualisierung der Recyclerview falsch? Android Studio log:

E/RecyclerView: No adapter attached; skipping layout 
I/Choreographer: Skipped 68 frames! The application may be doing too much work on its main thread. 

BikesAdapter:

public class BikesAdapter extends RecyclerView.Adapter<BikesAdapter.BikesViewHolder>{ 
    private static final String PREFS_NAME = "bikes_prefs"; 

    public static List<Categories> categories; 
    private Context context; 

    public BikesAdapter(Context context) { 
     this.context = context; 
     notifyDataSetChanged(); 
    } 

    @Override 
    public BikesViewHolder onCreateViewHolder(ViewGroup parent, int viewType) { 
     return new BikesViewHolder(LayoutInflater.from(parent.getContext()).inflate(R.layout.list_bikes, parent, false)); 
    } 

    @Override 
    public void onBindViewHolder(final BikesViewHolder holder, final int position) { 

     final SharedPreferences setFavoritesCnB = FragmentBikesListXT.context.getSharedPreferences(PREFS_NAME, MODE_PRIVATE); 
     boolean isFavoriteChB = setFavoritesCnB.getBoolean(categories.get(position).title, false); 
     holder.cbStars.setChecked(isFavoriteChB); 

     holder.cbStars.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       SharedPreferences.Editor editor = setFavoritesCnB.edit(); 
       editor.putBoolean(categories.get(position).title, holder.cbStars.isChecked()); 
       editor.apply(); 
       if (holder.cbStars.isChecked()) { 
        openDBHelper.save(position); 
        Constants.CATEGORIES.add(categories.get(position)); 
       } else { 
        openDBHelper.delete(position); 
        Constants.CATEGORIES.remove(categories.get(position)); 
       } 
      } 
     }); 

     if (checkSwitch) { 
      if (!isFavoriteChB) { 
       holder.cardView.setVisibility(View.GONE); 
      } else { 
       holder.textTitle.setText(categories.get(position).title); 
      } 

     } else holder.textTitle.setText(categories.get(position).title); 

     holder.textTitle.setOnClickListener(new View.OnClickListener() { 
      @Override 
      public void onClick(View v) { 
       Intent intent = new Intent(Intent.ACTION_VIEW); 
       intent.setData(Uri.parse(categories.get(position).link)); 
       context.startActivity(intent); 
      } 
     }); 
    } 

    @Override 
    public int getItemCount() { 
     return categories.size(); 
    } 

    public class BikesViewHolder extends RecyclerView.ViewHolder { 

     private CardView cardView; 
     private CheckBox cbStars; 
     private TextView textTitle; 

     public BikesViewHolder(View itemView) { 
      super(itemView); 

      cardView = (CardView) itemView.findViewById(R.id.cardView); 
      cbStars = (CheckBox) itemView.findViewById(R.id.cbStars); 
      textTitle = (TextView) itemView.findViewById(R.id.tv_title_bike); 
     } 
    } 
} 

Fragment mit recyclerview:

public class FragmentBikesListXT extends Fragment { 
    public static RecyclerView rvBikes; 
    public static ProgressBar pbBikes; 
    public static Context context; 

    public static CreateDBHelper dbHelper; 
    public static OpenDBHelper openDBHelper; 

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

     FrameLayout layout = (FrameLayout) inflater.inflate(R.layout.fragment_bikes_list_xt, container, false); 

     rvBikes = (RecyclerView) layout.findViewById(R.id.rvBikes); 
     pbBikes = (ProgressBar) layout.findViewById(R.id.pbBikes); 

     SharedPreferences setSwitch = getActivity().getSharedPreferences(PREFS_LIST, MODE_PRIVATE); 
     checkSwitch = setSwitch.getBoolean("NameOfThingToSave", false); 

     context = getContext(); 

     dbHelper = new CreateDBHelper(this.getActivity()); 
     openDBHelper = new OpenDBHelper(); 

     initIO(Constants.URL_FULL_LIST); 
     return layout; 
    } 

    public void initIO(String url) { 
     ParseXT.initializeData(url); 
     rvBikes.setHasFixedSize(true); 
     rvBikes.setLayoutManager(new GridLayoutManager(this.getActivity(), 1)); 
    } 
} 

SettingsActivity:

public class SettingsActivity extends AppCompatActivity { 

    private Switch mSwitch; 
    public static boolean checkSwitch; 
    public static final String PREFS_LIST = "list_prefs"; 
    public static Context context; 

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

     getSupportActionBar().setDisplayHomeAsUpEnabled(true); 
     getSupportActionBar().setHomeButtonEnabled(true); 

     mSwitch = (Switch) findViewById(R.id.switch_list); 
     SharedPreferences setSwitch = getSharedPreferences(PREFS_LIST, MODE_PRIVATE); 
     mSwitch.setChecked(setSwitch.getBoolean("NameOfThingToSave", false)); 

     mSwitch.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() { 
      @Override 
      public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) { 
       if(isChecked){ 
        checkSwitch = true; 
        SharedPreferences.Editor editor = getSharedPreferences(PREFS_LIST, MODE_PRIVATE).edit(); 
        editor.putBoolean("NameOfThingToSave", true); 
        editor.commit(); 

       }else{ 
        checkSwitch = false; 
        SharedPreferences.Editor editor = getSharedPreferences(PREFS_LIST, MODE_PRIVATE).edit(); 
        editor.putBoolean("NameOfThingToSave", false); 
        editor.commit(); 
       } 

      } 
     }); 
    } 

    @Override 
    public boolean onOptionsItemSelected(MenuItem item) { 
     switch (item.getItemId()) { 
      case android.R.id.home: 
       super.onBackPressed(); 
       return true; 
     } 
     finish(); 
     return super.onOptionsItemSelected(item); 
    } 
} 

OpenDBHelper:

public class OpenDBHelper implements IDBHelper { 
    private SQLiteDatabase db; 

    @Override 
    public void read() { 
     db = FragmentBikesListXT.dbHelper.getWritableDatabase(); 
     BikesAdapter.categories.clear(); 

     Cursor c = db.query(Constants.TABLE_BIKE, null, null, null, null, null, null); 

     if (c.moveToFirst()) { 
      int titleColIndex = c.getColumnIndex(Constants.FIELD_TITLE); 
      int linkColIndex = c.getColumnIndex(Constants.FIELD_LINK); 

      do { 
       BikesAdapter.categories.add(new Categories(
         c.getString(titleColIndex), 
         c.getString(linkColIndex))); 

       Log.d("DBHelper", "READ ID = " + c.getString(titleColIndex)); 

      } while (c.moveToNext()); 

     } else 
      c.close(); 
    } 

    @Override 
    public void save(int position) { 
     ContentValues cv = new ContentValues(); 
     db = FragmentBikesListXT.dbHelper.getWritableDatabase(); 
     cv.put(Constants.FIELD_TITLE, BikesAdapter.categories.get(position).title); 
     cv.put(Constants.FIELD_LINK, BikesAdapter.categories.get(position).link); 

     long size = db.insert(Constants.TABLE_BIKE, null, cv); 
     Log.d("DBHelper", "SAVE row inserted, size " + size + " ID = , " + BikesAdapter.categories.get(position).title); 

     FragmentBikesListXT.dbHelper.close(); 
    } 

    @Override 
    public void delete(int position) { 
     db = FragmentBikesListXT.dbHelper.getWritableDatabase(); 

     String[] whereArgs = {String.valueOf(BikesAdapter.categories.get(position).title)}; 
     db.delete(Constants.TABLE_BIKE, Constants.FIELD_TITLE + " = ?", whereArgs); 

     Log.d("DBHelper", "DELETE ID = " + BikesAdapter.categories.get(position).title); 

     db.close(); 
    } 
} 

Und Parser-Klasse:

public class ParseXT { 
    private static Elements titleTxt; 
    private static Elements linkTxt; 

    private static ArrayList<String> titleList = new ArrayList<>(); 
    private static ArrayList<String> linkList = new ArrayList<>(); 

    public static BikesAdapter bikesAdapter = new BikesAdapter(FragmentBikesListXT.context); 

    public static void initializeData(String url) { 

     new NewTreadParsed(url).execute(); 
    } 

    public static class NewTreadParsed extends AsyncTask<List<Categories>, Void, List<Categories>> { 
     private String url; 

     public NewTreadParsed(String url) { 
      this.url = url; 
     } 

     @Override 
     protected List<Categories> doInBackground(List<Categories>... params) { 
      Document doc; 
      List<Categories> categories = new ArrayList<>(); 
      try { 
       doc = Jsoup.connect(url).get(); 
       titleTxt = doc.select(".topictitle"); 
       linkTxt = doc.select(".a[href]"); 

       titleList.clear(); 
       linkList.clear(); 

       for (Element contents : titleTxt) { 
        titleList.add(contents.text()); 
       } 

       for (Element contents1 : titleTxt) { 
        Element element = contents1.select("a[href]").first(); 
        linkList.add(element.attr("abs:href")); 
       } 
      } 
      catch (IOException e){ 
       e.printStackTrace(); 
      } 
      for (int i = 0; i < titleList.size(); i++) { 
       categories.add(new Categories(titleList.get(i), linkList.get(i))); 
      } 
      return categories; 
     } 

     @Override 
     protected void onPostExecute(List<Categories> categories) { 
      super.onPostExecute(categories); 
      FragmentBikesListXT.pbBikes.setVisibility(ProgressBar.INVISIBLE); 
      BikesAdapter.categories = categories; 
      FragmentBikesListXT.rvBikes.setAdapter(bikesAdapter); 
     } 
    } 
} 

Answer 1

Verwenden notifyDataSetChanged() Wenn Sie einen Adapter schreiben es wird immer effizienter sein, die spezifischere Änderungsereignisse zu verwenden, wenn Sie können. Verlassen Sie sich auf notifyDataSetChanged()