Inconsistant null parameter handling in Reflection

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From: Stefan Hong (stefan_at_mosp.net)
Date: 11/09/04 

Date: Tue, 9 Nov 2004 14:09:22 +0800

Hi,

It seems that the way reflection resolves methods is not quite the same as
default CLR. For example this simple class:

  class Test {
    public void Hello(string name) {
      Console.WriteLine("Hello(string)");
    }
    public void Hello(object obj) {
      Console.WriteLine("Hello(object)");
    }
  }

If I invoke the method normally using null parameter:

  Test test = new Test();
  test.Hello(null); // shows Hello(string)

But if I only know the input parameter (which is null) and the name of the
method, and trying to use reflection to resolve the method to invoke, it
becomes:

  Test test = new Test();
  MethodInfo method = test.GetType().GetMethod("Hello", new Type[] {
typeof(void) });
  method.invoke(test, new object[] { null }); // shows Hello(object)

The result changed. It must because of the typeof(void) thing, but I can't
say typeof(string) because the input parameter is null. What should I do to
get the same result?

Thanks,
Stefan

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