Desktop.cs

using System;
using System.Runtime.InteropServices;

namespace VirtualDesktop
{
    public class Desktop
    {
        public static int Count
        {
            // Returns the number of desktops
            get { return DesktopManager.Manager.GetCount(); }
        }

        public static Desktop Current
        {
            // Returns current desktop
            get { return new Desktop(DesktopManager.Manager.GetCurrentDesktop()); }
        }

        public static Desktop FromIndex(int index)
        {
            // Create desktop object from index 0..Count-1
            return new Desktop(DesktopManager.GetDesktop(index));
        }

        //public static Guid GetId(IntPtr hWnd)
        //{
        //    return DesktopManager.WManager.GetWindowDesktopId(hWnd);
        //}

        public static Desktop FromWindow(IntPtr hWnd)
        {
            // Creates desktop object on which window <hWnd> is displayed
            Guid id = DesktopManager.WManager.GetWindowDesktopId(hWnd);
            return new Desktop(DesktopManager.Manager.FindDesktop(ref id));
        }

        public static Desktop Create()
        {
            // Create a new desktop
            return new Desktop(DesktopManager.Manager.CreateDesktop());
        }

        public void Remove(Desktop fallback = null)
        {
            // Destroy desktop and switch to <fallback>
            var back = fallback == null ? DesktopManager.GetDesktop(0) : fallback.itf;
            DesktopManager.Manager.RemoveDesktop(itf, back);
        }

        public bool IsVisible
        {
            // Returns <true> if this desktop is the current displayed one
            get { return object.ReferenceEquals(itf, DesktopManager.Manager.GetCurrentDesktop()); }
        }

        public void MakeVisible()
        {
            // Make this desktop visible
            DesktopManager.Manager.SwitchDesktop(itf);
        }

        public Desktop Left
        {
            // Returns desktop at the left of this one, null if none
            get
            {
                IVirtualDesktop desktop;
                int hr = DesktopManager.Manager.GetAdjacentDesktop(itf, 3, out desktop);
                if (hr == 0) return new Desktop(desktop);
                else return null;

            }
        }

        public Desktop Right
        {
            // Returns desktop at the right of this one, null if none
            get
            {
                IVirtualDesktop desktop;
                int hr = DesktopManager.Manager.GetAdjacentDesktop(itf, 4, out desktop);
                if (hr == 0) return new Desktop(desktop);
                else return null;
            }
        }

        public void MoveWindow(IntPtr handle)
        {
            // Move window <handle> to this desktop
            DesktopManager.WManager.MoveWindowToDesktop(handle, itf.GetId());
        }

        public bool HasWindow(IntPtr handle)
        {
            // Returns true if window <handle> is on this desktop
            return itf.GetId() == DesktopManager.WManager.GetWindowDesktopId(handle);
        }

        public override int GetHashCode()
        {
            return itf.GetHashCode();
        }
        public override bool Equals(object obj)
        {
            var desk = obj as Desktop;
            return desk != null && object.ReferenceEquals(this.itf, desk.itf);
        }

        public Guid Id()
        {
            return itf.GetId();
        }

        private IVirtualDesktop itf;
        private Desktop(IVirtualDesktop itf) { this.itf = itf; }
    }

    internal static class DesktopManager
    {
        static DesktopManager()
        {
            var shell = (IServiceProvider10)Activator.CreateInstance(Type.GetTypeFromCLSID(Guids.CLSID_ImmersiveShell));
            Manager = (IVirtualDesktopManagerInternal)shell.QueryService(Guids.CLSID_VirtualDesktopManagerInternal, Guids.IID_IVirtualDesktopManagerInternal);
            WManager = (IVirtualDesktopManager)Activator.CreateInstance(Type.GetTypeFromCLSID(Guids.CLSID_VirtualDesktopManager));
        }

        internal static IVirtualDesktop GetDesktop(int index)
        {
            int count = Manager.GetCount();
            if (index < 0 || index >= count) throw new ArgumentOutOfRangeException("index");
            IObjectArray desktops;
            Manager.GetDesktops(out desktops);
            object objdesk;
            desktops.GetAt(index, Guids.IID_IVirtualDesktop, out objdesk);
            Marshal.ReleaseComObject(desktops);
            return (IVirtualDesktop)objdesk;
        }

        internal static IVirtualDesktopManagerInternal Manager;
        internal static IVirtualDesktopManager WManager;
    }
}