将 Fragment 中 RecyclerView 的数据传递到另一个 Fragment

Question

I have application with RecycleView and after click on row I need open another RecycleView in another Fragment based on data which was in clicked row in first RecycleView. I had application where it was working, and now I want DrawerMenu and Fragments , and I don't know how to do it. I'm newbie on Android and all what I know is from tutorials.

BaseActivity

package cz.revelio.mhdapp;
import android.support.annotation.NonNull;
import android.support.design.widget.NavigationView;
import android.support.v4.view.GravityCompat;
import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.widget.Toolbar;
import android.view.MenuItem;
import android.widget.Toast;

public class BaseActivity extends AppCompatActivity implements NavigationView.OnNavigationItemSelectedListener {
    private DrawerLayout drawer;
@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);

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

    drawer = findViewById(R.id.drawer_layout);
    NavigationView navigationView = findViewById(R.id.nav_view);
    navigationView.setNavigationItemSelectedListener(this);

    ActionBarDrawerToggle toggle = new ActionBarDrawerToggle(this, drawer, toolbar,
            R.string.navigation_drawer_open, R.string.navigation_drawer_close);
    drawer.addDrawerListener(toggle);
    toggle.syncState();

    if (savedInstanceState == null) {
        getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                new ZapisFragment()).commit();
        navigationView.setCheckedItem(R.id.nav_message);
    }
}

@Override
public boolean onNavigationItemSelected(@NonNull MenuItem item) {
    switch (item.getItemId()) {

        case R.id.nav_chat:
            getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                    new ZapFragment()).commit();
            break;
        case R.id.nav_profile:
            getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                    new SeznamFragment()).commit();
            break;
        case R.id.nav_message:
            getSupportFragmentManager().beginTransaction().replace(R.id.fragment_container,
                    new ZapisFragment()).commit();
            break;
        case R.id.nav_share:
            Toast.makeText(this, "Share", Toast.LENGTH_SHORT).show();
            break;
        case R.id.nav_send:
            Toast.makeText(this, "Send", Toast.LENGTH_SHORT).show();
            break;
    }

    drawer.closeDrawer(GravityCompat.START);
    return true;
}

@Override
public void onBackPressed() {
    if (drawer.isDrawerOpen(GravityCompat.START)) {
        drawer.closeDrawer(GravityCompat.START);
    } else {
        super.onBackPressed();
    }
}
}

From BaseActivity I can call SeznamFragment where is first RecyclerView :

   package cz.revelio.mhdapp;

import android.os.Bundle;
import android.support.annotation.Nullable;
import android.support.v4.app.Fragment;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.content.Context;
import android.support.v7.widget.LinearLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.widget.TextView;
import android.widget.Toast;
import java.util.List;


public class SeznamFragment extends Fragment {
    RecyclerView recyclerView;
    DatabaseHelper mDatabaseHelper;
    TextView info;
    Context context;


@Nullable
@Override
public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View v =  inflater.inflate(R.layout.fragment_seznam, container, false);
    info = (TextView) v.findViewById(R.id.info_count_in_dash);
    recyclerView= (RecyclerView) v.findViewById(R.id.recyclerview);
    mDatabaseHelper = new DatabaseHelper(context);
    int vsechyZaznamy = mDatabaseHelper.getCountAllLogs();
    int unikatniZaznamy = mDatabaseHelper.getCountUniqueLogs();
    info.setText(vsechyZaznamy+" záznamů, z toho "+unikatniZaznamy+" unikátních.");
    getData();
    return v;
}

@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    context = getContext();

}
public void getData(){
    List<String> dataZaznamy = mDatabaseHelper.getAllLogs();
    String[] zaznamy = new String[dataZaznamy.size()];
    zaznamy = dataZaznamy.toArray(zaznamy);
    recyclerView.setLayoutManager(new LinearLayoutManager(context));
    recyclerView.setAdapter(new Adapter(context,zaznamy));
}


}

Adapter.java of RecycleView :

package cz.revelio.mhdapp;


import android.content.Context;
import android.content.Intent;
import android.os.Bundle;
import android.support.annotation.NonNull;
import android.support.constraint.ConstraintLayout;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v7.widget.RecyclerView;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class Adapter extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    Context context;
    String[] items;
    public Adapter(Context context, String[] items){
        this.context=context;
        this.items=items;
    }
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
    LayoutInflater inflater = LayoutInflater.from(context);
    View row = inflater.inflate(R.layout.costume_row, viewGroup, false);
    Item item=new Item(row);
    return item;
}

@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
    String text = items[position];
    final String casti[] = text.split(",");
    ((Item)viewHolder).itemName.setText(casti[0]);
    ((Item)viewHolder).itemCount.setText(casti[2]+"x");
    ((Item)viewHolder).itemLast.setText("Naposledy zapsáno:  "+casti[3]);
    ((Item) viewHolder).lay.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            //Toast.makeText(context, "OnClick Called on position "+position+" a lince "+ casti[0], Toast.LENGTH_SHORT).show();
         Fragment fragment = new VehicleFragment();
         Bundle b = new Bundle();
         b.putString("vehicle_id", casti[0]);
         fragment.setArguments(b);

         //android.support.v4.app.FragmentManager fragmentManager = get
          /*  Intent intent = new Intent(context, VehicleList.class);
            intent.putExtra("vehicle_id", casti[0]);
            context.startActivity(intent);*/
        }
    });
    ((Item) viewHolder).lay.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            //Toast.makeText(context, "OnLongClick Called on position "+position, Toast.LENGTH_SHORT).show();
            return true;
        }
    });
}



@Override
public int getItemCount() {
    return items.length;
}
public class Item extends RecyclerView.ViewHolder {
    TextView itemName;
    TextView itemCount;
    TextView itemLast;
    ConstraintLayout lay;

    public Item(View itemView){
        super(itemView);
        itemName= (TextView) itemView.findViewById(R.id.item_name);
        itemCount= (TextView) itemView.findViewById(R.id.item_count);
        itemLast= (TextView) itemView.findViewById(R.id.item_last);
        lay = (ConstraintLayout) itemView.findViewById(R.id.item_rr);
    }
}


}

VehicleFragment where is second RecyclerView and where I need data from SeznamFragment.java :

package cz.revelio.mhdapp;


import android.content.Context;
import android.content.Intent;
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.List;


public class VehicleFragment  extends Fragment {

    private static final String TAG = "LineList";
    RecyclerView recyclerView;
    DatabaseHelper mDatabaseHelper;
    Context context;
    String vehicle_id;
    @Nullable
    @Override
    public View onCreateView(LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
        return inflater.inflate(R.layout.fragment_seznam, container, false);

    }

@Override
public void onCreate(@Nullable Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    context = getContext();
    mDatabaseHelper = new DatabaseHelper(context);

    //getIncomingIntent();
}

/*private void getIncomingIntent(){

    if(getActivity().getIntent().hasExtra("vehicle_id")){
        String vehicle_id =  getActivity().getIntent().getStringExtra("vehicle_id");
        getData(vehicle_id);
    }
}*/

public void getData(String id_vehicle){
    List<String> dataZaznamy = mDatabaseHelper.getAllLogsByVehId(id_vehicle);
    String[] zaznamy = new String[dataZaznamy.size()];
    zaznamy = dataZaznamy.toArray(zaznamy);
    recyclerView.setLayoutManager(new LinearLayoutManager(context));
    recyclerView.setAdapter(new AdapterVehicle(context,zaznamy));
    }

}

AdapterVehicle of second RecyclerView :

package cz.revelio.mhdapp;



import android.app.AlertDialog;
import android.content.Context;
import android.content.DialogInterface;
import android.content.Intent;
import android.support.annotation.NonNull;
import android.support.constraint.ConstraintLayout;
import android.support.v7.widget.RecyclerView;
import android.text.Layout;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
import android.widget.Toast;

public class AdapterVehicle extends RecyclerView.Adapter<RecyclerView.ViewHolder> {
    DatabaseHelper mDatabaseHelper;
    Context context;
    String[] items;

    public AdapterVehicle(Context context, String[] items){
        this.context=context;
        this.items=items;

    }
    @Override
    public RecyclerView.ViewHolder onCreateViewHolder(ViewGroup viewGroup, int i) {
        LayoutInflater inflater = LayoutInflater.from(context);
        View row = inflater.inflate(R.layout.costume_row_veh, viewGroup, false);
        Item item=new Item(row);
        return item;
    }
@Override
public void onBindViewHolder(@NonNull RecyclerView.ViewHolder viewHolder, int position) {
    mDatabaseHelper = new DatabaseHelper(context);
    String text = items[position];
    final String casti[] = text.split(",");
    if(casti[5].equals("true")) {
        ((Item) viewHolder).itemName.setText("Jízda linkou " + casti[1]);
    }else{
        ((Item) viewHolder).itemName.setText("Linka " + casti[1]);
    }
    ((Item)viewHolder).itemCount.setText(casti[2]);
    ((Item)viewHolder).itemLast.setText(casti[3]);
    ((Item) viewHolder).lay.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View v) {
            // Toast.makeText(context, "OnClick Called on position "+position+" a lince "+ casti[0], Toast.LENGTH_SHORT).show();
            Intent intent = new Intent(context, VehicleEdit.class);
            intent.putExtra("vehicle_id", casti[0]);
            intent.putExtra("line", casti[1]);
            intent.putExtra("datum", casti[2]);
            intent.putExtra("cas", casti[3]);
            intent.putExtra("jedu", casti[5]);
            intent.putExtra("id", casti[4]);
            context.startActivity(intent);
        }
    });
    ((Item) viewHolder).lay.setOnLongClickListener(new View.OnLongClickListener() {
        @Override
        public boolean onLongClick(View v) {
            //Toast.makeText(context, "OnLongClick Called on position "+position, Toast.LENGTH_SHORT).show();
            //pass the 'context' here
            AlertDialog.Builder alertDialog = new AlertDialog.Builder(context);
            alertDialog.setTitle("Smazat záznam");
            alertDialog.setMessage("Chcete záznam smazat?");
            alertDialog.setPositiveButton("Ano", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {

                    Toast.makeText(context, "Záznam vozidla "+casti[0]+" na lince "+casti[1]+" byl smazán.", Toast.LENGTH_SHORT).show();
                    mDatabaseHelper.removeItem(casti[4]);
                    notifyDataSetChanged();
                    Intent intent = new Intent(context, SeznamFragment.class);
                    context.startActivity(intent);
                }
            });
            alertDialog.setNegativeButton("Ne", new DialogInterface.OnClickListener() {
                @Override
                public void onClick(DialogInterface dialog, int which) {
                    dialog.cancel();
                }
            });

            AlertDialog dialog = alertDialog.create();
            dialog.show();
            return true;
        }
    });
}

@Override
public int getItemCount() {
    return items.length;
}
public class Item extends RecyclerView.ViewHolder {
    TextView itemName;
    TextView itemCount;
    TextView itemLast;
    ConstraintLayout lay;

    public Item(View itemView){
        super(itemView);
        itemName= (TextView) itemView.findViewById(R.id.item_name_veh);
        itemCount= (TextView) itemView.findViewById(R.id.item_count_veh);
        itemLast= (TextView) itemView.findViewById(R.id.item_last_veh);
            lay = (ConstraintLayout) itemView.findViewById(R.id.item_rr_veh);
        }
    }
}

I tried another solutions from StackOvreflow but nothing work for me.

Here you can find my actual codes https://drive.google.com/file/d/1W6OzBCjwH4PJkix73woLCHHDBrh26-U1/view?usp=sharing

Answer 1

you can pass with Bundle :

public static VehicleFragment newInstance(String your_data_if_its_string) {
        VehicleFragment frag = new VehicleFragment();
        Bundle args = new Bundle();
        args.putString(PersonDBFields.ID, person_id);
        frag.setArguments(args);
        return frag;
    }

place it in your VehicleFragment , and use VehicleFragment.newInstance("yourData"); or you can create a field in your class and make a Setter for it , then call setter method instead of Bundle inside your new instance.

Answer 2

you are doing everything right except you are not adding it to the fragment manager that's why you are not able to start SecondFragment. Do it like this :

    VehicleFragment frag = new VehicleFragment();
    Bundle args = new Bundle();
    args.putString(PersonDBFields.ID, person_id);
    frag.setArguments(args);
    return frag;

//now add it to the fragment manager.like you are doing in your activity
getFragmentManager().beginTransaction().add(R.id.container, frag).commit();

In onCreateView of the new VehicleFragment:

//Retrieve the value
String value = getArguments().getString("YourKey");

you have to get the fragment manager inside your adapter class.

   @Override
    public void onClick(View view){
     VehicleFragment vehicleFragment =VehicleFragment.getInstance();
     Bundle b = new Bundle();
     b.putString("vehicle_id", casti[0]);
     vehicleFragment.setArguments(b);
    AppCompatActivity activity = (AppCompatActivity) view.getContext();         
    activity.getSupportFragmentManager().beginTransaction()
   .replace(R.id.fragment_container, 
    myFragment).addToBackStack(null).commit();

 }

Answer 3

Recently, Android Jetpack has some pretty good libraries that have ViewModel objects that make it easier to manage and store data. It lets you access data at different activities or fragments in an application. You try it and hope it will be useful to you