An Android Navigation Drawer that supports single and dual sliding drawers.

DrawerToggler.cs

using System;
using Android.App;
using Android.Support.V4.App;
using Android.Support.V4.Widget;
using Android.Views;

namespace FutureState.BreathingRoom.Droid.Ui
{
    public class ActionBarDrawerEventArgs : EventArgs
    {
        public View DrawerView { get; set; }
        public float SlideOffset { get; set; }
        public int NewState { get; set; }
    }

    public delegate void ActionBarDrawerChangedEventHandler(object s, ActionBarDrawerEventArgs e);

    public class DrawerToggler : ActionBarDrawerToggle
    {
        private readonly DrawerLayout _drawerLayout;
        private readonly View _leftDrawerView;
        private readonly View _rightDrawerView;

        public DrawerToggler(Activity activity, DrawerLayout drawerLayout, int drawerImageRes, int openDrawerContentDescRes, int closeDrawerContentDescRes)
            : base(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes)
        { }
        public DrawerToggler(Activity activity, DrawerLayout drawerLayout, int drawerImageRes, int openDrawerContentDescRes, int closeDrawerContentDescRes, View leftDrawerView, View rightDrawerView)
            : base(activity, drawerLayout, drawerImageRes, openDrawerContentDescRes, closeDrawerContentDescRes)
        {
            _drawerLayout = drawerLayout;
            _leftDrawerView = leftDrawerView;
            _rightDrawerView = rightDrawerView;
        }

        public event ActionBarDrawerChangedEventHandler DrawerClosed;
        public event ActionBarDrawerChangedEventHandler DrawerOpened;
        public event ActionBarDrawerChangedEventHandler DrawerSlide;
        public event ActionBarDrawerChangedEventHandler DrawerStateChanged;

        public override void OnDrawerClosed(View drawerView)
        {
            if (null != DrawerClosed)
                DrawerClosed(this, new ActionBarDrawerEventArgs { DrawerView = drawerView });
            base.OnDrawerClosed(drawerView);

            if (_leftDrawerView == null || _rightDrawerView == null || _drawerLayout == null) return;
            _drawerLayout.SetDrawerLockMode(DrawerLayout.LockModeUnlocked,
                                            drawerView == _rightDrawerView
                                            ? _leftDrawerView
                                            : _rightDrawerView);
        }

        public override void OnDrawerOpened(View drawerView)
        {
            if (null != DrawerOpened)
                DrawerOpened(this, new ActionBarDrawerEventArgs { DrawerView = drawerView });
            base.OnDrawerOpened(drawerView);

            if (_leftDrawerView == null || _rightDrawerView == null || _drawerLayout == null) return;
            _drawerLayout.SetDrawerLockMode(DrawerLayout.LockModeLockedClosed,
                                            drawerView == _rightDrawerView
                                            ? _leftDrawerView
                                            : _rightDrawerView);
        }

        public override void OnDrawerSlide(View drawerView, float slideOffset)
        {
            if (null != DrawerSlide)
                DrawerSlide(this, new ActionBarDrawerEventArgs
                    {
                        DrawerView = drawerView,
                        SlideOffset = slideOffset
                    });

            // only slide the left nav item
            // not working as I would like.
            if ((drawerView == _leftDrawerView) || (_leftDrawerView == null && _rightDrawerView == null))
            {
                base.OnDrawerSlide(drawerView, slideOffset);
            }
        }

        public override void OnDrawerStateChanged(int newState)
        {
            if (null != DrawerStateChanged)
                DrawerStateChanged(this, new ActionBarDrawerEventArgs
                    {
                        NewState = newState
                    });
            base.OnDrawerStateChanged(newState);
        }
    }
}

use.cs

        /// <summary>
        /// Navigation Drawer Configuration
        /// </summary>
        private void SetNavigationDrawerConfiguration()
        {
            // Left Drawer Config
            _drawerToggler = new DrawerToggler(this,
                                               _rootViewLayout,    // found using FindViewById
                                               Resource.Drawable.ic_drawer_light,
                                               Resource.String.drawer_open,
                                               Resource.String.drawer_close, 
                                               _leftDrawerLayout,  // found using FindViewById
                                               _rightDrawerLayout);// found using FindViewById

            _drawerToggler.DrawerClosed += delegate { InvalidateOptionsMenu(); };
            _drawerToggler.DrawerOpened += delegate
            {
                _leftDrawerList.SetItemChecked(_leftDrawerPosition, true);
                _rightDrawerList.SetItemChecked(_rightDrawerPosition, true);
                InvalidateOptionsMenu();
            };

            _rootViewLayout.SetDrawerShadow(Resource.Drawable.drawer_shadow_dark, (int)GravityFlags.Left); // left drawer shadow
            _rootViewLayout.SetDrawerShadow(Resource.Drawable.right_drawer_shadow_dark, (int)GravityFlags.Right); // right drawer shadow
            _rootViewLayout.SetDrawerListener(_drawerToggler);
        }