Fragment error in android navigation drawer

Question

Hello I'm getting expression expected error multiple times and I don't know what i'm doing wrong, if someone can help me that will be great. Thanks.

import android.support.v4.app.Fragment;
import android.app.Activity;
import android.app.ActionBar;
import android.app.FragmentManager;
import android.content.Context;
import android.os.Build;
import android.os.Bundle;
import android.view.Gravity;
import android.view.LayoutInflater;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;
import android.view.ViewGroup;
import android.support.v4.widget.DrawerLayout;
import android.widget.ArrayAdapter;
import android.widget.TextView;

public class MainActivity extends Activity
    implements NavigationDrawerFragment.NavigationDrawerCallbacks {

/**
 * Fragment managing the behaviors, interactions and presentation of the navigation drawer.
 */
private NavigationDrawerFragment mNavigationDrawerFragment;

/**
 * Used to store the last screen title. For use in {@link #restoreActionBar()}.
 */
private CharSequence mTitle;

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

    mNavigationDrawerFragment = (NavigationDrawerFragment)
            getFragmentManager().findFragmentById(R.id.navigation_drawer);
    mTitle = getTitle();

    // Set up the drawer.
    mNavigationDrawerFragment.setUp(
            R.id.navigation_drawer,
            (DrawerLayout) findViewById(R.id.drawer_layout));
}

@Override
public void onNavigationDrawerItemSelected(int position) {
    // update the main content by replacing fragments
    FragmentManager fragmentManager = getFragmentManager();
    fragmentManager.beginTransaction()
           .replace(R.id.container, Fragment) //expression expected error on "Fragment"
                .commit();
}

public void onSectionAttached(int position) {
    switch (position) {
        case 1:
            Fragment = new Welcome(); //expression expected error on "Fragment"
            break;
        case 2:
            Fragment = new Tutorials(); //expression expected error on "Fragment"
            break;
        case 3:
            Fragment = new Blueprints(); //expression expected error on "Fragment"
            break;
        case 4:
            Fragment = new Wiki(); //expression expected error on "Fragment"
            break;
        case 5:
            Fragment = new Chat(); //expression expected error on "Fragment"
            break;
        case 6:
            Fragment = new Item_Search(); //expression expected error on "Fragment"
            break;
        case 7:
            Fragment = new Recipes(); //expression expected error on "Fragment"
            break;
        case 8:
            Fragment = new Wallpaper(); //expression expected error on "Fragment"
            break;
        case 9:
            Fragment = new Maps_Mods(); //expression expected error on "Fragment"
            break;
        default :
            break;

    }
}



public void restoreActionBar() {
    ActionBar actionBar = getActionBar();
    actionBar.setNavigationMode(ActionBar.NAVIGATION_MODE_STANDARD);
    actionBar.setDisplayShowTitleEnabled(true);
    actionBar.setTitle(mTitle);
}


@Override
public boolean onCreateOptionsMenu(Menu menu) {
    if (!mNavigationDrawerFragment.isDrawerOpen()) {
        // Only show items in the action bar relevant to this screen
        // if the drawer is not showing. Otherwise, let the drawer
        // decide what to show in the action bar.
        getMenuInflater().inflate(R.menu.main, menu);
        restoreActionBar();
        return true;
    }
    return super.onCreateOptionsMenu(menu);
}

@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();
    if (id == R.id.action_settings) {
        return true;
    }
    return super.onOptionsItemSelected(item);
}

/**
 * A placeholder fragment containing a simple view.
 */
public static class PlaceholderFragment extends Fragment {
    /**
     * The fragment argument representing the section number for this
     * fragment.
     */
    private static final String ARG_SECTION_NUMBER = "section_number";

    /**
     * Returns a new instance of this fragment for the given section
     * number.
     */
    public static PlaceholderFragment newInstance(int sectionNumber) {
        PlaceholderFragment fragment = new PlaceholderFragment();
        Bundle args = new Bundle();
        args.putInt(ARG_SECTION_NUMBER, sectionNumber);
        fragment.setArguments(args);
        return fragment;
    }

    public PlaceholderFragment() {
    }

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.fragment_main, container, false);
        TextView textView = (TextView) rootView.findViewById(R.id.section_label);
        textView.setText(Integer.toString(getArguments().getInt(ARG_SECTION_NUMBER)));
        return rootView;
    }

    @Override
    public void onAttach(Activity activity) {
        super.onAttach(activity);
        ((MainActivity) activity).onSectionAttached(
                getArguments().getInt(ARG_SECTION_NUMBER));
    }
}

}

The error is underlining "Fragment". I'm trying to have the navigation drawer stitch to different fragments.

Answer 1

It should be

fragmentManager.beginTransaction()
       .replace(R.id.container,new Welcome())

and

Welcome fragment = new Welcome(); 

Similarly for others.

Since you are using support based Fragment. You need to change this

public class MainActivity extends Activity

to

public class MainActivity extends ActionBarActivity

if you need ActionBar. You also need to use AppCompat.

Check this

Navigation Drawer with backword compatibility android

Answer 2

Fragment is a key word. What you need is a variable of type Fragment. So, for example, put this in the same section as mTitle:

Fragment mFragment = null; 

In your switch statement, put, for example:

mFragment = new Welcome();

Then, when you're setting up the transaction, you can put:

fragmentManager.beginTransaction()
   .replace(R.id.container, mFragment)

This may not solve all your problems, but should get you past these compilation errors.