Embedding DLLs in a compiled executable

Question

Is it possible to embed a pre-existing DLL into a compiled C# executable (so that you only have one file to distribute)? If it is possible, how would one go about doing it?<

Answer 1

Neither the ILMerge approach nor Lars Holm Jensen's handling the AssemblyResolve event will work for a plugin host. Say executable H loads assembly P dynamically and accesses it via interface IP defined in an separate assembly. To embed IP into H one shall need a little modification to Lars's code:

Dictionary loaded = new Dictionary();
AppDomain.CurrentDomain.AssemblyResolve += (sender, args) =>
{   Assembly resAssembly;
    string dllName = args.Name.Contains(",") ? args.Name.Substring(0, args.Name.IndexOf(',')) : args.Name.Replace(".dll","");
    dllName = dllName.Replace(".", "_");
    if ( !loaded.ContainsKey( dllName ) )
    {   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);
        resAssembly = System.Reflection.Assembly.Load(bytes);
        loaded.Add(dllName, resAssembly);
    }
    else
    {   resAssembly = loaded[dllName];  }
    return resAssembly;
};  

The trick to handle repeated attempts to resolve the same assembly and return the existing one instead of creating a new instance.

EDIT: Lest it spoil .NET's serialization, make sure to return null for all assemblies not embedded in yours, thereby defaulting to the standard behaviour. You can get a list of these libraries by:

static HashSet IncludedAssemblies = new HashSet();
string[] resources = System.Reflection.Assembly.GetExecutingAssembly().GetManifestResourceNames();
for(int i = 0; i < resources.Length; i++)
{   IncludedAssemblies.Add(resources[i]);  }

and just return null if the passed assembly does not belong to IncludedAssemblies .