Get ProgID from .NET Assembly

Question

I want to write a program to find all the com visible .NET classes, and their ProgIDs from a .NET assembly. What's the best way to do this?

Answer 1

This will get the ProgId rather than the ClassId, and also work if the whole assembly is marked visible:

        Assembly assembly = Assembly.LoadFile("someassembly.dll");

        bool defaultVisibility;
        object[] assemblyAttributes = assembly.GetCustomAttributes(typeof(ComVisibleAttribute),false);
        if (assemblyAttributes.Length == 0)
            defaultVisibility = false;
        else
            defaultVisibility = (assemblyAttributes[0] as ComVisibleAttribute).Value;

        foreach(Type type in assembly.GetTypes())
        {
            bool isComVisible = defaultVisibility;
            object []attributes = type.GetCustomAttributes(typeof(ComVisibleAttribute),true);
            if (attributes.Length > 0)
                isComVisible = (attributes[0] as ComVisibleAttribute).Value;
            if (isComVisible)
            {
                attributes = type.GetCustomAttributes(typeof(ProgIdAttribute),true);
                if (attributes.Length >0)
                {
                    Console.WriteLine(String.Format("Type {0} has ProgID {1}",type.Name,(attributes[0] as ProgIdAttribute).Value));
                }
            }
        }