using System;
using System.IO;

namespace GetDllVersionDemo
{
    /// <summary>
    ///     https://www.cnblogs.com/LifeDecidesHappiness/p/15711169.html
    ///     C#判斷DLL檔案是32位還是64位
    ///     LDH @ 2021-12-20
    /// </summary>
    internal class Program
    {
        private static void Main()
        {
            Console.Title 
 
= "C#判斷DLL檔案是32位還是64位";

            GetDll32Or64();

            Console.ReadKey();
        }

        private static void GetDll32Or64()
        {
            var dllPath = Path.Combine(AppDomain.CurrentDomain.BaseDirectory, @"Dll\IBM.Data.Informix.dll");
            var result = GetPeArchitecture(dllPath);
            
 
//523 64位    267 32位
            if (result == 523)
                Console.WriteLine(dllPath + "是【64】位的dll");
            else if (result == 267)
                Console.WriteLine(dllPath + "是【32】位的dll");
            else
                Console.WriteLine("執行錯誤！");
        }

        /// <summary>
 

        ///     獲取dll檔案是32位還是64位
        ///     523 64位    267 32位
        /// </summary>
        /// <param name="dllFilePath">dll檔案路徑</param>
        /// <returns></returns>
        public static ushort GetPeArchitecture(string dllFilePath)
        {
            ushort architecture = 0;

            try
            {
                using (var fStream = new FileStream(dllFilePath, FileMode.Open, FileAccess.Read))
                {
                    using (var bReader = new BinaryReader(fStream))
                    {
                        if (bReader.ReadUInt16() == 23117) //check the MZ signature
                        {
                            fStream.Seek(0x3A, SeekOrigin.Current); //seek to e_lfanew.
                            fStream.Seek(bReader.ReadUInt32(), SeekOrigin.Begin); //seek to the start of the NT header.
                            if (bReader.ReadUInt32() == 17744) //check the PE\0\0 signature.
                            {
                                fStream.Seek(20, SeekOrigin.Current); //seek past the file header,
                                architecture = bReader.ReadUInt16(); //read the magic number of the optional header.
                            }
                        }
                    }
                }
            }
            catch
            {
                // ignored
            }

            // if architecture returns 0, there has been an error.
            return architecture;
        }
    }
}