Regular expression to restrict Extended ASCII character set

Question

I have multi lingual application which creates xml files but Extended ASCII characters from 168 to 254 (¿⌐¬½¼¡«»░▓│┤╡╢╖╕╣║╗╜╛┐└┴┬├) are not supposed in XML tags so, I would like

Answer 1

Rather you can make use of range in character class, to exclude specific range of characters using their Hex Codes: -

[^\xA8-\xFE]

The above regex will match any character except those in the given range. Those are the hex codes for the range you posted - [168, 254]

Answer 2

Although @Oded suggest was applicable but I used following solution:

Dim filteredInput as string

Private const XML_RESTRICTED_CHARACTERS as string ="[☺☻♥♦♣♠•◘○◙♂♀♪♫☼►◄↕‼¶§▬↨↑↓→←∟↔▲▼#$%&()*+,-./:;<=>?@[\]^_`¢£¥₧ƒªº¿⌐¬½¼¡«»░▒▓│┤╡╢╖╕╣║╗╝╜╛┐└┴┬├─┼╞╟╚╔╩╦╠═╬╧╨╤╥╙╘╒╓╫╪┘┌█▄▌▐▀αßΓπΣσµτΦΩδ∞φε∩≡±≥≤⌠⌡÷≈°∙·√ⁿ²■""}{]"

filteredInput =Regex.Replace(strInput.ToLower(), XML_RESTRICTED_CHARACTERS, "")

Answer 3

Second option was to create a string of all symbols from 168 to 254 and check if string contains any of them but not sure if it is reliable and accurate solution.

Yes, this is a reliable and accurate solution. It is also more lightweight than regular expressions.