RegularExpression in MVC 3

Question

I am using Regular expression for validation in my MVC 3 application.

in my app user need to be able to create folder on ftp. but folder name should only contains numbers,A-Z letters, a-z letters, _.

what ive got now :

[RegularExpression(@"[a-zåÅøØÆæA-Z-_0-9\s.]+")

I dont want user to be able to create white spaces after last letter/number in a string.

True value :

AsPnG 1.1

false value :

AsPnG 1.1"space""space"

Answer 1

Use following expression:

[a-zA-Z_0-9\s]*[a-zA-Z_0-9]