Invocations.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading.Tasks;

namespace ModLib
{
    internal static class Invocations
    {
        [StructLayout(LayoutKind.Sequential, CharSet = CharSet.Auto)]
        private 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(this);
            }
        }


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

        public static ulong GetAvailableMemory()
        {
            MEMORYSTATUSEX ex = new MEMORYSTATUSEX();
            if (GlobalMemoryStatusEx(ex))
            {
                return ex.ullAvailPhys;
            }

            return 0;
        }
    }
}