How to Create Navigation Drawer with Different Fragments in Android?

package com.example.navigation_drawer1;
 
import android.annotation.SuppressLint;
import android.app.Activity;
import android.content.res.Configuration;
import android.os.Bundle;
import android.support.v4.app.ActionBarDrawerToggle;
import android.support.v4.app.Fragment;
import android.support.v4.app.FragmentManager;
import android.support.v4.widget.DrawerLayout;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.ListView;
import android.widget.Toast;
 
@SuppressLint("NewApi")
public class MainActivity extends Activity {
    private String[] titles;
    private DrawerLayout layout_drawer;
    private ListView drawer_content;
    private ActionBarDrawerToggle action_bar_toggle;
    private CharSequence title;
 
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        title = getActionBar().getTitle();
        titles = getResources().getStringArray(R.array.operating_systems);
        layout_drawer = (DrawerLayout) findViewById(R.id.drawer_layout);
        drawer_content = (ListView) findViewById(R.id.left_drawer);
 
        drawer_content.setAdapter(new ArrayAdapter<String>(this,
                R.layout.fragment_layout, R.id.textView_fragment, titles));
        drawer_content.setOnItemClickListener(new DrawerItemClickListener());
 
        action_bar_toggle = new ActionBarDrawerToggle(this, /* Main Activity */
        layout_drawer, /* layput for navigation drawer */
        R.drawable.ic_drawer, R.string.open, /* on open drawer */
        R.string.close /* on close drawer */) {
 
            public void onDrawerClosed(View view) {
                getActionBar().setTitle(title);
            }
 
            public void onDrawerOpened(View drawerView) {
                getActionBar().setTitle("Open Drawer");
            }
        };
 
        layout_drawer.setDrawerListener(action_bar_toggle);
 
        getActionBar().setDisplayHomeAsUpEnabled(true);
        getActionBar().setHomeButtonEnabled(true);
 
    }
 
    private class DrawerItemClickListener implements
            ListView.OnItemClickListener {
        @Override
        public void onItemClick(AdapterView parent, View view, int position,
                long id) {
            selectItem(position);
        }
    }
 
    @Override
    protected void onPostCreate(Bundle savedInstanceState) {
        super.onPostCreate(savedInstanceState);
        action_bar_toggle.syncState();
    }
 
    @Override
    public void onConfigurationChanged(Configuration newConfig) {
        super.onConfigurationChanged(newConfig);
        action_bar_toggle.onConfigurationChanged(newConfig);
    }
 
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        getMenuInflater().inflate(R.menu.main, menu);
        return super.onCreateOptionsMenu(menu);
    }
 
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        if (action_bar_toggle.onOptionsItemSelected(item)) {
            return true;
        }
        switch (item.getItemId()) {
        case R.id.action_settings:
            Toast.makeText(this, "settings", Toast.LENGTH_LONG).show();
            break;
 
        default:
            break;
        }
        return super.onOptionsItemSelected(item);
    }
 
    private void selectItem(int position) {
        Class_Fragment fragment = new Class_Fragment();
        Bundle args = new Bundle();
        args.putInt(Class_Fragment.ARG_OS, position);
        fragment.setArguments(args);
        android.app.FragmentManager fragmentManager = getFragmentManager();
        fragmentManager.beginTransaction()
                .replace(R.id.content_frame, fragment).commit();
 
        drawer_content.setItemChecked(position, true);
        getActionBar().setTitle((titles[position]));
        layout_drawer.closeDrawer(drawer_content);
    }
 
}

package com.example.navigation_drawer1;
 
import android.app.Fragment;
import android.os.Bundle;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.TextView;
 
class Class_Fragment extends Fragment {
    public static final String ARG_OS = "OS";
    private String string;
 
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View view = inflater.inflate(R.layout.fragment_layout, null);
        TextView textView = (TextView) view
                .findViewById(R.id.textView_fragment);
        textView.setText(string);
        return view;
    }
 
    @Override
    public void onActivityCreated(Bundle savedInstanceState) {
        super.onActivityCreated(savedInstanceState);
    }
 
    @Override
    public void setArguments(Bundle args) {
        string = args.getString(ARG_OS);
    }
}