Create Class Library add this code in it
and add  namespace System.Runtime.InteropServices
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr FindWindow(string lpClassName, string lpWindowName);
    [DllImport("user32.dll", SetLastError = true)]
    static extern IntPtr GetWindow(IntPtr hWnd, GetWindow_Cmd uCmd);
    enum GetWindow_Cmd : uint
    {
        GW_HWNDFIRST = 0,
        GW_HWNDLAST = 1,
        GW_HWNDNEXT = 2,
        GW_HWNDPREV = 3,
        GW_OWNER = 4,
        GW_CHILD = 5,
        GW_ENABLEDPOPUP = 6
    }
    [DllImport("user32.dll", CharSet = CharSet.Auto)]
    static extern IntPtr SendMessage(IntPtr hWnd, UInt32 Msg, IntPtr wParam, IntPtr lParam);
    private const int WM_COMMAND = 0x111;
   public static void ToggleDesktopIcons()
    {
        var toggleDesktopCommand = new IntPtr(0x7402);
        IntPtr hWnd = GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD);
        SendMessage(hWnd, WM_COMMAND, toggleDesktopCommand, IntPtr.Zero);
    }
    [return: MarshalAs(UnmanagedType.Bool)]
    [DllImport("user32.dll", SetLastError = true)]
    private static extern bool GetWindowInfo(IntPtr hwnd, ref WINDOWINFO pwi);
    [StructLayout(LayoutKind.Sequential)]
    public struct RECT
    {
        private int _Left;
        private int _Top;
        private int _Right;
        private int _Bottom;
    }
    [StructLayout(LayoutKind.Sequential)]
    struct WINDOWINFO
    {
        public uint cbSize;
        public RECT rcWindow;
        public RECT rcClient;
        public uint dwStyle;
        public uint dwExStyle;
        public uint dwWindowStatus;
        public uint cxWindowBorders;
        public uint cyWindowBorders;
        public ushort atomWindowType;
        public ushort wCreatorVersion;
        public WINDOWINFO(Boolean? filler)
            : this()   // Allows automatic initialization of "cbSize" with "new WINDOWINFO(null/true/false)".
        {
            cbSize = (UInt32)(Marshal.SizeOf(typeof(WINDOWINFO)));
        }
    }
   public static bool IsVisible()
    {
        IntPtr hWnd = GetWindow(GetWindow(FindWindow("Progman", "Program Manager"), GetWindow_Cmd.GW_CHILD), GetWindow_Cmd.GW_CHILD);
        WINDOWINFO info = new WINDOWINFO();
        info.cbSize = (uint)Marshal.SizeOf(info);
        GetWindowInfo(hWnd, ref info);
        return (info.dwStyle & 0x10000000) == 0x10000000;
    }
add this dll reference to your project..
and call dllClass_name.ToggleDesktopIcon();