How to Configure Library Files to Run in a Subfolder?

Question

Hello

There is a library named TolkDotNet.dll in a c# wpf project. This library references various dll files in the x86 and x64 folders. To get rid of the file confusion, I placed them in the Lib folder as TolkDotNet, x86, x64. Then I showed the Lib/TolkDotNet.dll reference in the project dependencies. But the application looks for these dll files and folders in the project output directory. Therefore, the project is causing problems. How can I configure these references to run in the Lib folder?

Thanks.

Answer 1

To change the path that references an assembly, see https://learn.microsoft.com/en-us/dotnet/framework/configure-apps/specify-assembly-location.

Use LoadLibrary to switch to a native dll at runtime.

using System;
using System.IO;
using System.Runtime.InteropServices;

internal class Program
{
    static Program() {
        var pathToDll = Environment.Is64BitProcess ? @".\x64" : @".\x86";
        LoadLibrary(Path.Combine(pathToDll, "YourNative.dll"));
    }

    [DllImport("kernel32", SetLastError = true, CharSet = CharSet.Auto)]
    static extern IntPtr LoadLibrary(string lpFileName);

    [DllImport("YourNative.dll")]
    internal static extern IntPtr YourNativeFunction();

    static void Main(string[] args) {
        Console.WriteLine($"{YourNativeFunction()}");
        Console.ReadKey();
    }
}

Answer 2

Hi,

the above answer would work if the library mentioned by OP (TolkDotNet.dll) is unmanaged/native winPE that exports symbols. I suspect that is not the case (I did not bother to google since the name says it all) - so this TolkDotNet.dll seems to use other native libraries using interop and would load appropriate runtime based on the platform being invoked on.

that said - you can consider a commercial/free obfuscator tool (I have experience with redgate SmartAssembly) and it allowed me to bundle all custom dependencies in a single executable file/dll with the dependencies embedded as encrypted binary blobs within the main assembly.

i hope that helps you assess your options -

1. The x86/64 folder needs to exist wherever the tolkdotnet.dll is , and it can not be the GAC so
2. add a manifest file and specify the folder you would like to load this DLL from - it can be any folder on the file system - even outside your solution- however that would create a deployment chore for you to ensure that you package and deploy the same configuration to a target machine (maybe it’s not even required in OPs scenario so I would leave it at that)

Answer 3

Hello

No matter what I did, I couldn't use the dll file in the subdirectory properly at runtime. The error still persists. Could you help me by trying the TolkDotNet library in a WPF project?

Thank you.