OnValidate VB.Net partial method wont fire for NerdDinner sample code

Answer 1

I figured this out (more or less). I got the order of the two parameters backwards...

ret.Add(New RuleViolation("Quantity", "Quantity is not numeric"))

should be

ret.Add(New RuleViolation("Quantity is not numeric", "Quantity"))

I still don't fill that I fully understand this. Oh well.