我想按TabLayout中的片段更改RecyclerView列表数据

Question

I Want to change RecyclerView list data by fragment in TabLayout . I want to remove old data and i want to put my own data into app, I am new so i do not know how to reomove and how to put new data

MainActivity :

package baleli.urdupoetrybytariq;

import android.os.Bundle;
import android.support.design.widget.TabLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.app.FragmentPagerAdapter;
import android.support.v4.view.ViewPager;
import android.support.v7.app.AppCompatActivity;
import android.support.v7.widget.Toolbar;
import android.util.Log;

import java.util.ArrayList;
import java.util.List;

public class MainActivity extends AppCompatActivity {
    private static Toolbar toolbar;
    private static ViewPager viewPager;
    private static TabLayout tabLayout;

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

        toolbar = (Toolbar) findViewById(R.id.toolbar);
        setSupportActionBar(toolbar);

        viewPager = (ViewPager) findViewById(R.id.viewPager);
        setupViewPager(viewPager);

        tabLayout = (TabLayout) findViewById(R.id.tabLayout);
        tabLayout.setupWithViewPager(viewPager);//setting tab over viewpager

        //Implementing tab selected listener over tablayout
        tabLayout.setOnTabSelectedListener(new TabLayout.OnTabSelectedListener() {
            @Override
            public void onTabSelected(TabLayout.Tab tab) {
                viewPager.setCurrentItem(tab.getPosition());//setting current selected item over viewpager
                switch (tab.getPosition()) {
                    case 0:
                        Log.e("TAG","TAB1");
                        break;
                    case 1:
                        Log.e("TAG","TAB2");
                        break;
                    case 2:
                        Log.e("TAG","TAB3");
                        break;
                }
            }

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

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


    //Setting View Pager
    private void setupViewPager(ViewPager viewPager) {
        ViewPagerAdapter adapter = new ViewPagerAdapter(getSupportFragmentManager());
        adapter.addFrag(new DummyFragment("Item"), "Love Poetry");
        adapter.addFrag(new DummyFragment("Item"), "Bewafa Poetry");
        adapter.addFrag(new DummyFragment("Item"), "Sad Poetry");
        viewPager.setAdapter(adapter);
    }


    //View Pager fragments setting adapter class
    class ViewPagerAdapter extends FragmentPagerAdapter {
        private final List<Fragment> mFragmentList = new ArrayList<>();//fragment arraylist
        private final List<String> mFragmentTitleList = new ArrayList<>();//title arraylist

        public ViewPagerAdapter(FragmentManager manager) {
            super(manager);
        }

        @Override
        public Fragment getItem(int position) {
            return mFragmentList.get(position);
        }

        @Override
        public int getCount() {
            return mFragmentList.size();
        }


        //adding fragments and title method
        public void addFrag(Fragment fragment, String title) {
            mFragmentList.add(fragment);
            mFragmentTitleList.add(title);
        }

        @Override
        public CharSequence getPageTitle(int position) {
            return mFragmentTitleList.get(position);
        }
    }
}

Recyclerview_Adapter :

package baleli.urdupoetrybytariq;

import android.content.Context;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.ViewGroup;

import java.util.ArrayList;

/**
 * Created by SONU on 10/09/15.
 */
public class RecyclerView_Adapter extends
        RecyclerView.Adapter<DemoViewHolder> {
    private ArrayList<String> arrayList;
    private Context context;


    public RecyclerView_Adapter(Context context,
                                ArrayList<String> arrayList) {
        this.context = context;
        this.arrayList = arrayList;

    }


    @Override
    public int getItemCount() {
        return (null != arrayList ? arrayList.size() : 0);

    }

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


        final DemoViewHolder mainHolder = (DemoViewHolder) holder;
        //Setting text over textview
        mainHolder.title.setText(arrayList.get(position));

    }

    @Override
    public DemoViewHolder onCreateViewHolder(
            ViewGroup viewGroup, int viewType) {
        LayoutInflater mInflater = LayoutInflater.from(viewGroup.getContext());

        ViewGroup mainGroup = (ViewGroup) mInflater.inflate(
                R.layout.item_row, viewGroup, false);
        DemoViewHolder mainHolder = new DemoViewHolder(mainGroup) {
            @Override
            public String toString() {
                return super.toString();
            }
        };


        return mainHolder;

    }


}

DummyFragment :

package baleli.urdupoetrybytariq;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;

import java.util.ArrayList;

import baleli.urdupoetrybytariq.R;

/**
 * Created by SONU on 16/09/15.
 */
public class DummyFragment extends Fragment {
    private View view;

    private String title;//String for tab title

    private static RecyclerView recyclerView;

    public DummyFragment() {
    }

    public DummyFragment(String title) {
        this.title = title;//Setting tab title
    }

    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {
        view = inflater.inflate(R.layout.dummy_fragment, container, false);

        setRecyclerView();
        return view;

    }
    //Setting recycler view
    private void setRecyclerView() {

        recyclerView = (RecyclerView) view
                .findViewById(R.id.recyclerView);
        recyclerView.setHasFixedSize(true);
        recyclerView
                .setLayoutManager(new LinearLayoutManager(getActivity()));//Linear Items


        ArrayList<String> arrayList = new ArrayList<>();
        for (int i = 0; i < 50; i++) {
            arrayList.add(title+"" + i);//Adding items to recycler view
        }
        RecyclerView_Adapter adapter = new RecyclerView_Adapter(getActivity(), arrayList);
        recyclerView.setAdapter(adapter);// set adapter on recyclerview

    }
}

DemoViewHolder :

package baleli.urdupoetrybytariq;

import android.support.v7.widget.RecyclerView;
import android.view.View;
import android.widget.TextView;

/**
 * Created by SONU on 31/08/15.
 */
public abstract class DemoViewHolder extends RecyclerView.ViewHolder {


    public TextView title;


    public DemoViewHolder(View view) {
        super(view);


        this.title = (TextView) view.findViewById(R.id.cardTitle);

    }


}

Answer 1

Here you are using loop to insert data into your ArrayList .

Change your below code to my code :

DummyFragment.java :

YOUR CODE :

 ArrayList<String> arrayList = new ArrayList<>();
        for (int i = 0; i < 20; i++) {
            arrayList.add(title+" Items " + i);//Adding items to recycler view
        }

CHANGE TO BELOW CODE :

 ArrayList<String> arrayList = new ArrayList<>();
        arrayList.add("First Data");
        arrayList.add("Second Data");
        arrayList.add("Third Data");
        arrayList.add("Fourth Data");
        arrayList.add("Fifth Data");
        arrayList.add("Sixth Data"); //As like your can insert data to your ArrayList.

Answer 2

In Simple way, You have to clear your existing ArrayList and than do notifyDataSetChanged to notify adapter data is changed and than add new data to Arrayist make sure Arrayist you send to adapter will not change ref while adding new data. and call again notifyDataSetChanged to tell adapter you have new data to show.

That's all you have to do. Cheer!. let me know if u have any question