Skip to content
Switch branches/tags


Failed to load latest commit information.



LegacyWrapper uses a wrapper process to call dlls from a process of the opposing architecture (X86 or AMD64).

Since you can't load a dll of another architecture directly, the wrapper utilizes a named pipe to abstract the call. You won't notice this though, because all the magic is hidden behind a single static method.

NuGet Package

There is a NuGet package available here: Codefoundry.LegacyWrapper @


If you want to compile the LegacyWrapper yourself, make sure to place both the wrapper executable, LegacyWrapperClient.dll and LegacyWrapper.Common.dll in your directory.

// Define a proxy interface with matching method names and signatures
// The interface must be derived from IDisposable!
public interface IUser32Dll : IDisposable
    [LegacyDllMethod(CallingConvention = CallingConvention.Winapi)]
    int GetSystemMetrics(int nIndex);

// Create configuration
IWrapperConfig configuration = WrapperConfigBuilder.Create()

// Create new Wrapper client providing the proxy interface
// Remember to ensure a call to the Dispose()-Method!
using (var client = WrapperProxyFactory<IUser32Dll>.GetInstance(configuration))
    // Make calls - it's that simple!
    int x = client.GetSystemMetrics(0);
    int y = client.GetSystemMetrics(1);

Please note that loading a 64bit dll will only work on 64bit operating systems.

Further reading

View this blog post to obtain a basic understanding of how the library works internally.


Feel free to submit any suggestions/issues and contribute to LegacyWrapper.


Copyright (c) 2019, Franz Wimmer. (MIT License)

See LICENSE for more info.