c# - Activator.CreateInstance with private sealed class

Question

I'm trying to new up a LocalCommand instance which is a private class of System.Data.SqlClient.SqlCommandSet. I seem to be able to grab the type information just fine:

Assembly sysData = Assembly.Load("System.Data, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089");
localCmdType = sysData.GetType("System.Data.SqlClient.SqlCommandSet+LocalCommand");

but Activator.CreateInstance throws an exception when I try to instantiate it:

object item = Activator.CreateInstance(localCmdType,
  new object[] { commandText, parameters, num7, commandType });

System.MissingMethodException: Constructor on type 'System.Data.SqlClient.SqlCommandSet+LocalCommand' not found.

The constructor arguments match the signature I see in Reflector. Is new'ing up a private class with an internal ctor supported with a different CreateInstance overload or what?

Answer 1

My first thought would be to get the ConstructorInfo using ConstructorInfo constructorInfo = Type.GetConstructor(), and then constructorInfo.Invoke() that. I suspect that Activator.CreateInstance makes it hard to call constructors you wouldn't normally have access to, although I don't remember trying it myself.