How can a C++ windows dll be merged into a C# application exe?

Question

I have a Windows C# program that uses a C++ dll for data i/o. My goal is to deploy the application as a single EXE.

What are the steps to create such an executable?

Answer 1

Single Assembly Deployment of Managed and Unmanaged Code Sunday, February 4, 2007

.NET developers love XCOPY deployment. And they love single assembly components. At least I always feel kinda uneasy, if I have to use some component and need remember a list of files to also include with the main assembly of that component. So when I recently had to develop a managed code component and had to augment it with some unmanaged code from a C DLL (thx to Marcus Heege for helping me with this!), I thought about how to make it easier to deploy the two DLLs. If this were just two assemblies I could have used ILmerge to pack them up in just one file. But this doesn´t work for mixed code components with managed as well as unmanaged DLLs.

So here´s what I came up with for a solution:

I include whatever DLLs I want to deploy with my component´s main assembly as embedded resources. Then I set up a class constructor to extract those DLLs like below. The class ctor is called just once within each AppDomain so it´s a neglible overhead, I think.

namespace MyLib
{
    public class MyClass
    {
        static MyClass()
        {
            ResourceExtractor.ExtractResourceToFile("MyLib.ManagedService.dll", "managedservice.dll");
            ResourceExtractor.ExtractResourceToFile("MyLib.UnmanagedService.dll", "unmanagedservice.dll");
        }

        ...

In this example I included two DLLs as resources, one being an unmanaged code DLL, and one being a managed code DLL (just for demonstration purposes), to show, how this technique works for both kinds of code.

The code to extract the DLLs into files of their own is simple:

public static class ResourceExtractor
{
    public static void ExtractResourceToFile(string resourceName, string filename)
    {
        if (!System.IO.File.Exists(filename))
            using (System.IO.Stream s = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceStream(resourceName))
                using (System.IO.FileStream fs = new System.IO.FileStream(filename, System.IO.FileMode.Create))
                {
                    byte[] b = new byte[s.Length];
                    s.Read(b, 0, b.Length);
                    fs.Write(b, 0, b.Length);
                }
    }
}

Working with a managed code assembly like this is the same as usual - almost. You reference it (here: ManagedService.dll) in your component´s main project (here: MyLib), but set the Copy Local property to false. Additionally you link in the assembly as an Existing Item and set the Build Action to Embedded Resource.

For the unmanaged code (here: UnmanagedService.dll) you just link in the DLL as an Existing Item and set the Build Action to Embedded Resource. To access its functions use the DllImport attribute as usual, e.g.

[DllImport("unmanagedservice.dll")] public extern static int Add(int a, int b);

That´s it! As soon as you create the first instance of the class with the static ctor the embedded DLLs get extracted into files of their own and are ready to use as if you deployed them as separate files. As long as you have write permissions for the execution directory this should work fine for you. At least for prototypical code I think this way of single assembly deployment is quite convenient.

Enjoy!

http://weblogs.asp.net/ralfw/archive/2007/02/04/single-assembly-deployment-of-managed-and-unmanaged-code.aspx

Answer 2

Try boxedapp; it allows to load all DLLs from memory. Also, it seems that you can even embed .net runtime. Good to create a really standalone applications...

Answer 3

Use Fody.Costura nuget

1. Open your solution -> Project -> Manage Nuget Packages
2. Search for Fody.Costura
3. Compile your project.

That's it !

Source: http://www.manuelmeyer.net/2016/01/net-power-tip-10-merging-assemblies/

Answer 4

Have you tried ILMerge? http://research.microsoft.com/~mbarnett/ILMerge.aspx

ILMerge is a utility that can be used to merge multiple .NET assemblies into a single assembly. It is freely available for use from the Tools & Utilities page at the Microsoft .NET Framework Developer Center.

If you're building the C++ DLL with the /clr flag (all or partially C++/CLI), then it should work:

ilmerge /out:Composite.exe MyMainApp.exe Utility.dll

It will not work with an ordinary (native) Windows DLL however.

Answer 5

Just right-click your project in Visual Studio, choose Project Properties -> Resources -> Add Resource -> Add Existing File… And include the code below to your App.xaml.cs or equivalent.

public App()
{
    AppDomain.CurrentDomain.AssemblyResolve +=new ResolveEventHandler(CurrentDomain_AssemblyResolve);
}

System.Reflection.Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
    string dllName = args.Name.Contains(',') ? args.Name.Substring(0, args.Name.IndexOf(',')) : args.Name.Replace(".dll","");

    dllName = dllName.Replace(".", "_");

    if (dllName.EndsWith("_resources")) return null;

    System.Resources.ResourceManager rm = new System.Resources.ResourceManager(GetType().Namespace + ".Properties.Resources", System.Reflection.Assembly.GetExecutingAssembly());

    byte[] bytes = (byte[])rm.GetObject(dllName);

    return System.Reflection.Assembly.Load(bytes);
}

Here's my original blog post: http://codeblog.larsholm.net/2011/06/embed-dlls-easily-in-a-net-assembly/

Answer 6

Thinstall is one solution. For a native windows application I would suggest embedding the DLL as a binary resource object, then extracting it at runtime before you need it.

Answer 7

Smart Assembly can do this and more. If your dll has unmanaged code, it wont let you merge the dlls to a single assembly, instead it can embed the required dependencies as resources to your main exe. Its flip-side, its not free.

You can do this manually by embedding dll to your resources and then relying on AppDomain's Assembly ResolveHandler. When it comes to mixed mode dlls, I found many of the variants and flavours of ResolveHandler approach to not work for me (all which read dll bytes to memory and read from it). They all worked for managed dlls. Here is what worked for me:

static void Main()
{
    AppDomain.CurrentDomain.AssemblyResolve += (sender, args) =>
    {
        string assemblyName = new AssemblyName(args.Name).Name;
        if (assemblyName.EndsWith(".resources"))
            return null;

        string dllName = assemblyName + ".dll";
        string dllFullPath = Path.Combine(GetMyApplicationSpecificPath(), dllName);

        using (Stream s = Assembly.GetEntryAssembly().GetManifestResourceStream(typeof(Program).Namespace + ".Resources." + dllName))
        {
            byte[] data = new byte[stream.Length];
            s.Read(data, 0, data.Length);

            //or just byte[] data = new BinaryReader(s).ReadBytes((int)s.Length);

            File.WriteAllBytes(dllFullPath, data);
        }

        return Assembly.LoadFrom(dllFullPath);
    };
}

The key here is to write the bytes to a file and load from its location. To avoid chicken and egg problem, you have to ensure you declare the handler before accessing assembly and that you do not access the assembly members (or instantiate anything that has to deal with the assembly) inside the loading (assembly resolving) part. Also take care to ensure GetMyApplicationSpecificPath() is not any temp directory since temp files could be attempted to get erased by other programs or by yourself (not that it will get deleted while your program is accessing the dll, but at least its a nuisance. AppData is good location). Also note that you have to write the bytes each time, you cant load from location just 'cos the dll already resides there.

If the assembly is fully unmanaged, you can see this link or this as to how to load such dlls.

Answer 8

PostBuild from Xenocode can package up both managed and unmanged into a single exe.