AppDomain.CurrentDomain.AssemblyResolve asking for a .resources assembly?

Question

using the code How to embed a satellite assembly into the EXE file provided by csharptest.net, I\'ve created a custom assembly resolver and embedded my assemblies in my reso

Answer 1

My situation was a bit more complex and the above solution did not work for me. (That is changing the AssemblyInfo.cs file)

I have moved all my form and image resources to a seperate dll and the moment any of the images are used the 'filenotfoundexception' exception is thrown.

The important information is the following:
Beginning with the .NET Framework 4, the ResolveEventHandler event is raised for all assemblies, including resource assemblies. See the following reference

https://msdn.microsoft.com/en-us/library/system.appdomain.assemblyresolve(v=vs.110).aspx

The solution turned out to be very simple. If a resource file is requested in the form 'dllname.resources.dll' always return null;

Here is the event code that I have adapted from other samples found. (I have commented the debugging lines - un-comment them if you have a problem using the code.

Add this line in your class. It is used to prevent loading a dll more than once

    readonly static Dictionary<string, Assembly> _libs = new Dictionary<string, Assembly>();

This is the event method.

private static Assembly OnAssemblyResolve(object sender, ResolveEventArgs args)
        {
            Assembly assembly = null;
            string keyName = new AssemblyName(args.Name).Name;
            if (keyName.Contains(".resources"))
            {
                return null;  // This line is what fixed the problem
            }
            if (_libs.ContainsKey(keyName))
            {
                assembly = _libs[keyName]; // If DLL is loaded then don't load it again just return
                return assembly;
            }

            string dllName = DllResourceName(keyName);
            //string[] names = Assembly.GetExecutingAssembly().GetManifestResourceNames();   // Uncomment this line to debug the possible values for dllName
            using (Stream stream = Assembly.GetExecutingAssembly().GetManifestResourceStream(dllName))
            {
                if (stream == null)
                {
                    Debug.Print("Error! Unable to find '" + dllName + "'");
                    // Uncomment the next lines to show message the moment an assembly is not found. (This will also stop for .Net assemblies
                    //MessageBox.Show("Error! Unable to find '" + dllName + "'! Application will terminate.");
                    //Environment.Exit(0);
                    return null;
                }

                byte[] buffer = new BinaryReader(stream).ReadBytes((int) stream.Length);
                assembly = Assembly.Load(buffer);

                _libs[keyName] = assembly;
                return assembly;
            }
        }

        private static string DllResourceName(string ddlName)
        {
            if (ddlName.Contains(".dll") == false) ddlName += ".dll";

            foreach (string name in Assembly.GetExecutingAssembly().GetManifestResourceNames())
            {
                if (name.EndsWith(ddlName)) return name;
            }
            return ddlName;
        }

Answer 2

Answering on my own;

Adding this line to AssemblyInfo.cs solves it and resolver will not get asked for resources any-more.

[assembly: NeutralResourcesLanguageAttribute("en-US", UltimateResourceFallbackLocation.MainAssembly)]

Though this is a work-around should be carefully considered multi-language applications.

More Info:

• https://connect.microsoft.com/VisualStudio/feedback/details/526836/wpf-appdomain-assemblyresolve-being-called-when-it-shouldnt
• http://blogs.msdn.com/b/kimhamil/archive/2008/11/11/what-does-the-neutralresourceslanguageattribute-do.aspx
• http://forums.devshed.com/net-development-87/c-wpf-appdomain-assemblyresolve-being-called-when-it-shouldn-t-669567.html
• http://blogs.msdn.com/b/microsoft_press/archive/2010/02/03/jeffrey-richter-excerpt-2-from-clr-via-c-third-edition.aspx

This approach fails for machines with non en-US cultures. A better approach is ignoring resources on assembly resolver;

public Assembly Resolver(object sender, ResolveEventArgs args)
        {
            lock (this)
            {
                Assembly assembly;
                AssemblyName askedAssembly = new AssemblyName(args.Name);

                string[] fields = args.Name.Split(',');
                string name = fields[0];
                string culture = fields[2];
                // failing to ignore queries for satellite resource assemblies or using [assembly: NeutralResourcesLanguage("en-US", UltimateResourceFallbackLocation.MainAssembly)] 
                // in AssemblyInfo.cs will crash the program on non en-US based system cultures.
                if (name.EndsWith(".resources") && !culture.EndsWith("neutral")) return null;

                /* the actual assembly resolver */
                ...
            }
      }