Question

In my ASP.NET MVC app I’m using a small helper to iterate through all the controllers.
This helper is located at a different assembly than my MVC app and I’m referencing to it.

The problem is, that when calling the Assembly.GetCallingAssembly() method in the helper, it doesn’t returns the MVC app assembly, but it returns the helper assembly instead.
This is not what I’m expecting to get, because all my controllers are living in the MVC app assembly and I need to reflect it.

The view code(MVC app assembly):

<nav>
   <ul id="menu">
      @foreach(var item in new MvcHelper().GetControllerNames())
      {
         @Html.ActionMenuItem(
              (string)HttpContext.GetGlobalResourceObject("StringsResourse", item), "Index",
              item)
      }
   </ul>
</nav>

The Helper code(independent assembly):

public class MvcHelper
{
    public  List<string> GetControllerNames()
    {
        var controllerNames = new List<string>();
        GetSubClasses<Controller>().ForEach(
            type => controllerNames.Add(type.Name));
        return controllerNames;
    }

    private static List<Type> GetSubClasses<T>()
    {
        return Assembly.GetCallingAssembly().GetTypes().Where(
            type => type.IsSubclassOf(typeof(T))).ToList();
    }
}

What am I doing wrong here?

Answer 1

What am I doing wrong here?

Nothing. You are probably missing the fact that Razor views are compiled as separate assemblies by the ASP.NET runtime. Those assemblies are dynamic. They have nothing to do with your ASP.NET MVC application assembly. And since you are calling the helper in your view the Assembly.GetCallingAssembly() method will return something like this:

App_Web_fqxdopd5, Version=0.0.0.0, Culture=neutral, PublicKeyToken=null

If you want to get all controllers why not just loop through all referenced assemblies and look for types deriving from Controller? You could use the AppDomain.CurrentDomain.GetAssemblies() method for this. Then for each assembly just GetTypes() and filter upon:

public class MvcHelper
{
    private static List<Type> GetSubClasses<T>()
    {
        return AppDomain
            .CurrentDomain
            .GetAssemblies()
            .SelectMany(
                a => a.GetTypes().Where(type => type.IsSubclassOf(typeof(T)))
            ).ToList();
    }

    public List<string> GetControllerNames()
    {
        var controllerNames = new List<string>();
        GetSubClasses<Controller>().ForEach(
            type => controllerNames.Add(type.Name));
        return controllerNames;
    }
}