public void GetProps(Parent p){ // want to access lots of child properties here string childProp1 = p.prop1; bool childProp2 = p.prop2; bool childProp3
The solution in case someone need it, it is just to cast the class you receive as a reference as follows:
public void GetProps(Parent p){ .. string childProp1 = ((ChildClass)p).prop1; ... }