Same Navigation Drawer on different Activities

BaseActivity.java

public class BaseActivity extends AppCompatActivity 
{
	public DrawerLayout drawerLayout;
    public ListView drawerList;
    private ActionBarDrawerToggle drawerToggle;
	
    protected void onCreate(Bundle savedInstanceState)
    {
    	// R.id.drawer_layout should be in every activity with exactly the same id.
    	drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);
    	
    	drawerToggle = new ActionBarDrawerToggle((Activity) this, drawerLayout, R.drawable.ic_drawer, 0, 0) 
    	{
	        public void onDrawerClosed(View view) 
	        {
	            getActionBar().setTitle(R.string.app_name);
	        }
	
	        public void onDrawerOpened(View drawerView) 
	        {
	            getActionBar().setTitle(R.string.menu);
	        }
	    };
	    drawerLayout.setDrawerListener(drawerToggle);
	
	    getActionBar().setDisplayHomeAsUpEnabled(true);
	    getActionBar().setHomeButtonEnabled(true);
	    
	    drawerList = (ListView) findViewById(R.id.left_drawer);
	    drawerList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_activated_1,
	            items)); //Items is an ArrayList or array with the items you want to put in the Navigation Drawer.
	
	    drawerList.setOnItemClickListener(new OnItemClickListener() {
	        @Override
	        public void onItemClick(AdapterView<?> arg0, View arg1, int pos, long arg3) {
	            // Do what you want when an item from the Navigation Drawer is clicked
	        }
	    });
    }
    
    @Override
	public boolean onOptionsItemSelected(MenuItem item) {
	
	    if (drawerToggle.onOptionsItemSelected(item)) {
	        return true;
	    }
	    return super.onOptionsItemSelected(item);
	
	}
	
	@Override
	protected void onPostCreate(Bundle savedInstanceState) {
	    super.onPostCreate(savedInstanceState);
	    drawerToggle.syncState();
	}
	
	@Override
	public void onConfigurationChanged(Configuration newConfig) {
	    super.onConfigurationChanged(newConfig);
	    drawerToggle.onConfigurationChanged(newConfig);
	}
}

Hi, I want to include a navigation menu in all of the activities. I used the code "BaseActivity.java" and extended all other activities to BaseActivity. i have an issue, when I try to call one of my activities i get the following runtime exception

Unable to start activity ComponentInfo{lecho.lib.hellocharts.samples.app.wicedsense/lecho.lib.hellocharts.samples.blog_activity}: java.lang.NullPointerException: Attempt to invoke virtual method 'void android.support.v4.app.ActionBarDrawerToggle.syncState()' on a null object reference

The following is the code which I modified:

` public class BaseActivity extends AppCompatActivity
{
public DrawerLayout drawerLayout;
public ListView drawerList;
private ActionBarDrawerToggle drawerToggle;
public String[] layers;
private CharSequence mTitle;
private CharSequence mDrawerTitle;

protected void onCreateDrawer(Bundle savedInstanceState)
{
super.onCreate(savedInstanceState);
mTitle =mDrawerTitle=getTitle();
drawerLayout = (DrawerLayout) findViewById(R.id.drawer_layout);

    drawerToggle = new ActionBarDrawerToggle((Activity) this, drawerLayout, R.drawable.ic_drawer, 0, 0)
    {
        public void onDrawerClosed(View view)
        {
            getSupportActionBar().setTitle(mTitle);
            invalidateOptionsMenu();
        }

       public void onDrawerOpened(View drawerView)
        {
            getSupportActionBar().setTitle(mDrawerTitle);
            invalidateOptionsMenu();
        }
    };
    drawerLayout.setDrawerListener(drawerToggle);

    getActionBar().setDisplayHomeAsUpEnabled(true);
    getActionBar().setHomeButtonEnabled(true);
    layers = getResources().getStringArray(R.array.nav_drawer_items);
    drawerList = (ListView) findViewById(R.id.list_slidermenu);
    drawerList.setAdapter(new ArrayAdapter<String>(this, android.R.layout.simple_list_item_activated_1,
            android.R.id.text1,layers)); //Items is an ArrayList or array with the items you want to put in the Navigation Drawer.

    drawerList.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> arg0, View arg1, int pos, long arg3) {
            // Do what you want when an item from the Navigation Drawer is clicked
        }
    });
}

@Override
public boolean onOptionsItemSelected(MenuItem item) {

    if (drawerToggle.onOptionsItemSelected(item)) {
        return true;
    }
    return super.onOptionsItemSelected(item);

}

@Override
protected void onPostCreate(Bundle savedInstanceState) {
    super.onPostCreate(savedInstanceState);
    drawerToggle.syncState();
}

@Override
public void onConfigurationChanged(Configuration newConfig) {
    super.onConfigurationChanged(newConfig);
    drawerToggle.onConfigurationChanged(newConfig);
}

}`

I get an exception at this point: drawerLayout.setDrawerListener(drawerToggle);
And i also found out that setting a title was producing an Nullpointer exception getSupportActionBar().setTitle(mTitle); and getSupportActionBar().setTitle(mDrawerTitle);

My question is do I need to hard code the title or is there any other smart way of doing it.

I get an exception at this point: drawerLayout.setDrawerListener(drawerToggle);

Look at line 9: R.id.drawer_layout should be in every activity with exactly the same id. Your drawerLayout equals null at this point.

Thanks , I Needed This

drawerLayout.setDrawerListener(drawerToggle);
java.lang.NullPointerException

How to color the background of the selected item

I've followed everything what you given but every activity I am getting bellow error don't know why
"android.view.InflateException: Binary XML file line #28: Attempt to invoke virtual method 'boolean java.lang.String.equals(java.lang.Object)' on a null object reference"