Every once and awhile I find the need to get a reference to a Type maintained in a separate assembly. This tends to happen when I am loading assemblies at runtime and am trying to build an instance of a known Type in that assembly. In fact, this is how my XmlProvider class builds instances. Well I have found that the built in System.Reflection.Emit.TypeBuilder.GetType(…) method does not deal well with these advanced situations. So here is a very inefficient, brute force method for getting the Type object you need. Also note that I have included some tags for cross-platform compatibility. I am still looking for a workaround for the Zune and Xbox 360.

///

/// Handles cross assembly type referencing by searching loaded assemblies for a type.
/// 

public static class TypeBuilder
{
    public static Type[] GetBaseTypes(Type type)
    {
        List types = new List();

        Type t = type;
        while (t.BaseType != null)
        {
            if (t.BaseType == typeof(Object))
                break;

            types.Add(t.BaseType);

            t = t.BaseType;
        }

        return types.ToArray();
    }

    ///

    /// Gets the Type object for a specific type name.
    /// 

    ///
The type name to search.
    /// A Type object.
    /// Searches assemblies only loaded in the current application domain.
    /// 
    public static Type GetType(string typeName)
    {
#if ZUNE
        return null;
#else
        if (String.IsNullOrEmpty(typeName))
            throw new ArgumentException("Provided type name was invalid.");

        // Get a list of assemblies first...
        Assembly[] assemblies = AppDomain.CurrentDomain.GetAssemblies();

        // Loop through until we find the type.
        foreach (Assembly assembly in assemblies)
        {
            Type t = assembly.GetType(typeName);

            if (t == null)
            {
                Type[] ts = assembly.GetTypes();

                foreach (Type type in ts)
                    if (type.Name == typeName || type.AssemblyQualifiedName == typeName)
                        return type;
            }

            if (t != null)
                return t;
        }

        // We may need to fall back on the built in builder.
        return System.Reflection.Emit.TypeBuilder.GetType(typeName);
#endif
    }
}