Как использовать gridview во фрагменте?

Question

Я хочу использовать GridView во фрагменте, но не показывает элементы GridView, когда приложение запускается просто показать пустую страницу. но когда я помещаю код в новый проект или в работу, работа корректно.

почти каждый GridView или RecyclerView, который я вставил во фрагмент, не работает.

Помогите мне, пожалуйста.

Frag.java

import android.app.Activity;
import android.content.Context;
import android.os.Bundle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentActivity;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import uk.co.chrisjenx.calligraphy.CalligraphyContextWrapper;

public class Frag1 extends Fragment {


    public Frag1() {
        // Required empty public constructor

    }


    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
                             Bundle savedInstanceState) {
        // Inflate the layout for this fragment
        return inflater.inflate(R.layout.frag1, container, false);
    }

    }

Frag1.xml

<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:padding="8dp"
        tools:context=".LoveMain">

        <android.support.v7.widget.RecyclerView
            android:id="@+id/recycler_view"
            android:layout_width="match_parent"
            android:layout_height="match_parent"
            android:scrollbars="vertical" />

    </RelativeLayout>

</LinearLayout>

Card_view.xml

<android.support.v7.widget.CardView
    xmlns:card_view="http://schemas.android.com/apk/res-auto"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/card_view"
    android:layout_width="80dp"
    android:layout_height="wrap_content"
    card_view:cardUseCompatPadding="true"
    card_view:cardCornerRadius="8dp"
    android:layout_marginBottom="16dp">

    <RelativeLayout
        android:layout_width="match_parent"
        android:layout_height="match_parent">

        <ImageView
            android:id="@+id/country_photo"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:contentDescription="@string/action_settings"
            android:src="@drawable/three"
            android:scaleType="centerCrop" />

        <TextView
            android:id="@+id/country_name"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:textSize="13sp"
            android:text="@string/country_name"
            android:textColor="@color/colorAccent"
            android:gravity="center"
            android:layout_below="@+id/country_photo"
            android:paddingBottom="8dp"
            android:paddingTop="8dp"
            android:layout_alignParentBottom="true"
            android:background="@color/colorPrimaryDark"/>

    </RelativeLayout>

</android.support.v7.widget.CardView>

GridView.java

import android.os.Bundle;
import android.support.v7.app.ActionBarActivity;
import android.support.v7.widget.GridLayoutManager;
import android.support.v7.widget.RecyclerView;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.Toast;

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


public class LoveMain extends ActionBarActivity {

    private GridLayoutManager lLayout;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.frag1);
        setTitle(null);

        Toolbar topToolBar = (Toolbar)findViewById(R.id.toolbar);
        setSupportActionBar(topToolBar);
        topToolBar.setLogo(R.drawable.logo);
        topToolBar.setLogoDescription(getResources().getString(R.string.logo_desc));

        List<ItemObject> rowListItem = getAllItemList();
        lLayout = new GridLayoutManager(LoveMain.this, 4);

        RecyclerView rView = (RecyclerView)findViewById(R.id.recycler_view);
        rView.setHasFixedSize(true);
        rView.setLayoutManager(lLayout);

        RecyclerViewAdapter rcAdapter = new RecyclerViewAdapter(LoveMain.this, rowListItem);
        rView.setAdapter(rcAdapter);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        // Inflate the menu; this adds items to the action bar if it is present.
        getMenuInflater().inflate(R.menu.main, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        // Handle action bar item clicks here. The action bar will
        // automatically handle clicks on the Home/Up button, so long
        // as you specify a parent activity in AndroidManifest.xml.
        int id = item.getItemId();

        //noinspection SimplifiableIfStatement
        if (id == R.id.action_settings) {
            return true;
        }
        if(id == R.id.action_refresh){
            Toast.makeText(LoveMain.this, "Refresh App", Toast.LENGTH_LONG).show();
        }
        if(id == R.id.action_new){
            Toast.makeText(LoveMain.this, "Create Text", Toast.LENGTH_LONG).show();
        }

        return super.onOptionsItemSelected(item);
    }

    private List<ItemObject> getAllItemList(){

        List<ItemObject> allItems = new ArrayList<ItemObject>();
        allItems.add(new ItemObject("United States", R.drawable.one));
        allItems.add(new ItemObject("Canada", R.drawable.two));
        allItems.add(new ItemObject("United Kingdom", R.drawable.three));
        allItems.add(new ItemObject("Germany", R.drawable.four));
        allItems.add(new ItemObject("Sweden", R.drawable.five));
        allItems.add(new ItemObject("United Kingdom", R.drawable.six));
        allItems.add(new ItemObject("Germany", R.drawable.seven));
        allItems.add(new ItemObject("Sweden", R.drawable.eight));
        allItems.add(new ItemObject("United States", R.drawable.one));
        allItems.add(new ItemObject("Canada", R.drawable.two));
        allItems.add(new ItemObject("United Kingdom", R.drawable.three));
        allItems.add(new ItemObject("Germany", R.drawable.four));
        allItems.add(new ItemObject("Sweden", R.drawable.five));
        allItems.add(new ItemObject("United Kingdom", R.drawable.six));
        allItems.add(new ItemObject("Germany", R.drawable.seven));
        allItems.add(new ItemObject("Sweden", R.drawable.eight));

        return allItems;
    }