SystemTrayMenu/NativeDllImport/TrackPopupMenuEx.cs

using System;
using System.Runtime.InteropServices;

namespace SystemTrayMenu.DllImports
{
    public static partial class NativeMethods
    {
        // The TrackPopupMenuEx function displays a shortcut menu at the specified location and tracks the selection of items on the shortcut menu. The shortcut menu can appear anywhere on the screen.
        [DllImport("user32.dll", ExactSpelling = true, CharSet = CharSet.Unicode)]
        private static extern uint TrackPopupMenuEx(IntPtr hmenu, TPM flags, int x, int y, IntPtr hwnd, IntPtr lptpm);

        internal static uint User32TrackPopupMenuEx(IntPtr hmenu, TPM flags, int x, int y, IntPtr hwnd, IntPtr lptpm)
        {
            return TrackPopupMenuEx(hmenu, flags, x, y, hwnd, lptpm);
        }

        // Specifies how TrackPopupMenuEx positions the shortcut menu horizontally
        [Flags]
        internal enum TPM : uint
        {
            LEFTBUTTON = 0x0000,
            RIGHTBUTTON = 0x0002,
            LEFTALIGN = 0x0000,
            CENTERALIGN = 0x0004,
            RIGHTALIGN = 0x0008,
            TOPALIGN = 0x0000,
            VCENTERALIGN = 0x0010,
            BOTTOMALIGN = 0x0020,
            HORIZONTAL = 0x0000,
            VERTICAL = 0x0040,
            NONOTIFY = 0x0080,
            RETURNCMD = 0x0100,
            RECURSE = 0x0001,
            HORPOSANIMATION = 0x0400,
            HORNEGANIMATION = 0x0800,
            VERPOSANIMATION = 0x1000,
            VERNEGANIMATION = 0x2000,
            NOANIMATION = 0x4000,
            LAYOUTRTL = 0x8000
        }
    }
}