using System;
using System.IO;

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

        /// <summary>
///     獲取dll文件是32位還是64位
///     523 64位    267 32位
/// </summary>
/// <param name="dllFilePath">dll文件路徑</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;
}
}
}