Android - Cannot find symbol variable drawer_open when implementing navigation bar

Question

I'm trying to implement a navigation bar within my android application. However, my compilers complains with following errors:

Error:(39, 25) error: cannot find symbol variable drawer_open

Error:(39, 47) error: cannot find symbol variable drawer_close

My code:

import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;



public class MainActivity extends ActionBarActivity {
    /***********************************************************
                            MEMBERS
     **********************************************************/
    private Toolbar m_toolbar;
    private String m_navTitles[] = {"Nr. 1", "Nr. 2", "Nr. 3", "Nr. 4" };
    private int m_icons[] = {R.drawable.ic_action, R.drawable.ic_action, R.drawable.ic_action, R.drawable.ic_action};
    private DrawerLayout m_drawer;
    private ActionBarDrawerToggle m_drawerToggle;

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

        /* Set toolbar */
        m_toolbar = (Toolbar) findViewById(R.id.tool_bar); //find toolbar from layout
        setSupportActionBar(m_toolbar); //call to set toolbar as the ActionBar

        /* Set navigation drawer */
        m_drawer = (DrawerLayout) findViewById(R.id.DrawerLayout); //assign drawer object to view
        m_drawerToggle = new ActionBarDrawerToggle(this, m_drawer, m_toolbar, R.string.drawer_open, R.string.drawer_close){
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                // code here will execute once the drawer is opened
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                // Code here will execute once drawer is closed
            }

        }; // made drawer toggle object
        m_drawer.setDrawerListener(m_drawerToggle);
        m_drawerToggle.syncState();               
    }

Please note that my code for the navigation drawer is not finished yet. I wanted to fix the drawer_open/drawer_close errors first.

Many thanks in advance!

Answer 1

Did you have drawer_open and drawer_close in your strings.xml?

I think you didn't add these two strings in your strings.

Answer 2

Try this Your pbm is solved here copy this code and replace yours :

import android.support.v4.widget.DrawerLayout;
import android.support.v7.app.ActionBarActivity;
import android.os.Bundle;
import android.support.v7.app.ActionBarDrawerToggle;
import android.support.v7.widget.Toolbar;
import android.view.Menu;
import android.view.MenuItem;
import android.view.View;



public class MainActivity extends ActionBarActivity {
    /***********************************************************
                            MEMBERS
     **********************************************************/
    private Toolbar m_toolbar;
    private String m_navTitles[] = {"Nr. 1", "Nr. 2", "Nr. 3", "Nr. 4" };
    private int m_icons[] = {R.drawable.ic_action, R.drawable.ic_action, R.drawable.ic_action, R.drawable.ic_action};
    private DrawerLayout m_drawer;
    private ActionBarDrawerToggle m_drawerToggle;

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

        /* Set toolbar */
        m_toolbar = (Toolbar) findViewById(R.id.tool_bar); //find toolbar from layout
        setSupportActionBar(m_toolbar); //call to set toolbar as the ActionBar

        /* Set navigation drawer */
        m_drawer = (DrawerLayout) findViewById(R.id.DrawerLayout); //assign drawer object to view
        m_drawerToggle = new ActionBarDrawerToggle(this, m_drawer, m_toolbar, "drawer_open", "drawer_close"){
            @Override
            public void onDrawerOpened(View drawerView) {
                super.onDrawerOpened(drawerView);
                // code here will execute once the drawer is opened
            }

            @Override
            public void onDrawerClosed(View drawerView) {
                super.onDrawerClosed(drawerView);
                // Code here will execute once drawer is closed
            }

        }; // made drawer toggle object
        m_drawer.setDrawerListener(m_drawerToggle);
        m_drawerToggle.syncState();               
    }