First off, the code above works perfectly as is without modification. My problem was the way I was implementing it.

I’m writing a console application and, even using this code, I kept getting a System.IO.FileNotFoundException error:

Could not load file or assembly ‘MyEmbeddedAssembly, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null’ or one of its dependencies. The system cannot find the file specified.

Following Vincent’s post above, I had created a “loader” class whose sole purpose was to instantiate another class and terminate. This way, I wasn’t “using” the embedded DLL before I tried to load it into memory.

The problem was, the code above (as is), creates a class constructor called App. For a console application, at least, the class constructor does not get called upon launching the EXE.

To address this, you have two options:

1) You can modify the code above to be a static function in your “loader” class.
or
2) You can create a third class named something like EmbeddedAssemblyLoader. In your Main() in the Loader class, you first instantiate the EmbeddedAssemblyLoader class, then you instantiate whatever class you have that needed MyEmbeddedAssembly.

Option 1:
namespace MyApp
{
class Loader
{
static void Main(string[] args)
{
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);

MyNeedyClass mnc = new MyNeedyClass(args);

return;
}
static System.Reflection.Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
Debug.WriteLine(“CurrentDomain_AssemblyResolve intercepted request for ” + args.Name);

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(typeof(MyApp).Namespace + “.Properties.Resources”, System.Reflection.Assembly.GetExecutingAssembly());

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

Debug.WriteLine(“CurrentDomain_AssemblyResolve is loading ” + dllName);

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

Option 2:
namespace MyApp
{
class Loader
{
static void Main(string[] args)
{
EmbeddedAssemblyLoader eal = new EmbeddedAssemblyLoader();

MyNeedyClass mnc = new MyNeedyClass(args);

return;
}
}
class EmbeddedAssemblyLoader
{
public EmbeddedAssemblyLoader()
{
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);
}

System.Reflection.Assembly CurrentDomain_AssemblyResolve(object sender, ResolveEventArgs args)
{
Debug.WriteLine(“EmbeddedAssemblyLoader intercepted request for ” + args.Name);

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);

Debug.WriteLine(“EmbeddedAssemblyLoader is loading ” + dllName);

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

Thanks for publishing this. I can’t get this to work, I’ve created a very simple solution to show what I’m doing.

I have a DLL that has one function, called ReturnA(). All it does is return the character ‘A’. Its source code is:

namespace ClassLibrary1
{
public class Class1
{
public static char ReturnA()
{
return ‘A’;
}
}
}

I then have a simple console application that just tries to call this function. As you posted, I added a reference to the DLL, and I also added it as a resource in resources/ClassLibrary1.dll. I selected “Embedded Resource” as a build action. The code for the console app is:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using ClassLibrary1;
using System.Reflection;

namespace ConsoleApplication1
{
class Program
{
static void Main(string[] command_line_args)
{
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);

Console.WriteLine(“Testing to write a line before embedded DLL function is called”);
Caller caller = new Caller();
caller.WriteToLine();
}

static 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(typeof(Program).Namespace + “.Properties.Resources”, System.Reflection.Assembly.GetExecutingAssembly());
byte[] bytes = (byte[])rm.GetObject(dllName);
return System.Reflection.Assembly.Load(bytes);
}
}

public class Caller
{
public void WriteToLine()
{
char foo = Class1.ReturnA();
Console.WriteLine(foo);
Console.ReadLine();
}
}
}

When I call this application from the command line, it doesn’t work if the ClassLibrary1.dll file isn’t in the same directory. As far as I can tell, I have followed your instructions completely. I even put the call to the DLL function in another class, just to make sure.

I have the solution available at: http://bit.ly/P9N86L

Thank you for any help!

When I used the solution above, I am getting the below error.

Could not load file or assembly ‘ServiceAgent, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null’ or one of its dependenciesAn expected resource in the assembly manifest was missing. (Exception from HRESULT: 0×80131532)

My scenario is I have a DLL_1 which is using several other dlls. I added all these dependent dlls as resources and updated properties to Embedded Resource.

I have a client application (.Exe), included DLL_1. I added following code in program.cs (.Exe)

[STAThread]
static void Main()
{
AppDomain.CurrentDomain.AssemblyResolve += new ResolveEventHandler(CurrentDomain_AssemblyResolve);

Application.EnableVisualStyles();
Application.SetCompatibleTextRenderingDefault(false);
Application.Run(new Form1());
}

static 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(typeof(Program).Namespace + “.Properties.Resources”, System.Reflection.Assembly.GetExecutingAssembly());

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

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

}

Not sure why I am getting the error. I appreciate your help.

Thanks,
Rao.