Machine Memory Status - Win32Memory

    public class Win32Memory
    {
        [return: MarshalAs(UnmanagedType.Bool)]
        [DllImport("kernel32.dll", CharSet = CharSet.Auto, SetLastError = true)]
        static extern bool GlobalMemoryStatusEx([In, Out] MEMORYSTATUSEX lpBuffer);

        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        class MEMORYSTATUSEX
        {
            public uint dwLength;
            public uint dwMemoryLoad;
            public ulong ullTotalPhys;
            public ulong ullAvailPhys;
            public ulong ullTotalPageFile;
            public ulong ullAvailPageFile;
            public ulong ullTotalVirtual;
            public ulong ullAvailVirtual;
            public ulong ullAvailExtendedVirtual;
            public MEMORYSTATUSEX()
            {
                this.dwLength = (uint)Marshal.SizeOf(typeof(MEMORYSTATUSEX));
            }
        }

        public static Win32MemoryInfo GetTotalMemory()
        {
            MEMORYSTATUSEX memStatus = new MEMORYSTATUSEX();
            if (GlobalMemoryStatusEx(memStatus))
            {
                Win32MemoryInfo minfo = new Win32MemoryInfo();
                minfo.TotalPhys = (long)memStatus.ullTotalPhys;
                minfo.AvailPhys = (long)memStatus.ullAvailPhys;
                minfo.TotalPageFile = (long)memStatus.ullTotalPageFile;
                minfo.AvailPageFile = (long)memStatus.ullAvailPageFile;
                minfo.TotalVirtual = (long)memStatus.ullTotalVirtual;
                minfo.AvailVirtual = (long)memStatus.ullAvailVirtual;
                minfo.AvailExtendedVirtual = (long)memStatus.ullAvailExtendedVirtual;
                return minfo;
            }
            return null;
        }

        public class Win32MemoryInfo
        {
            public long TotalPhys { get; set; }
            public long AvailPhys { get; set; }
            public long TotalPageFile { get; set; }
            public long AvailPageFile { get; set; }
            public long TotalVirtual { get; set; }
            public long AvailVirtual { get; set; }
            public long AvailExtendedVirtual { get; set; }
        }
    }