Inspired by Validators for Windows Forms - ValidationProvider Control article from Code project. Original article date, 16 Apr 2005. 10 years old but still works! http://www.codeproject.com/Articles/10093/Validators-for-Windows-Forms-ValidationProvider-Co
I thought this code will be available in github but, its not. so, decided to putting it here AS-IS and fix the bugs I have come across.
This is a really great library for validation in windows forms.