iOS 7新增了几个URL相关的Character Set。但是文档并不全面,下面是打印出来的所有值
URLFragmentAllowedCharacterSet: !$&'()*+,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~
URLPasswordAllowedCharacterSet: !$&'()*+,-.0123456789;=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~
URLPathAllowedCharacterSet: !$&'()*+,-./0123456789:=@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~
URLQueryAllowedCharacterSet: !$&'()*+,-./0123456789:;=?@ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~
URLUserAllowedCharacterSet: !$&'()*+,-.0123456789;=ABCDEFGHIJKLMNOPQRSTUVWXYZ_abcdefghijklmnopqrstuvwxyz~