How to: Strip Invalid Characters from a String
The following code example uses the static Regex.Replace method to strip invalid characters from a string. You can use the CleanInput method defined in this example to strip potentially harmful characters that have been entered into a text field in a form that accepts user input. In this case, CleanInput strips out all nonalphanumeric characters except periods (.), at symbols (@), and hyphens (-), and returns the remaining string. However, you can modify the regular expression pattern so that it strips out any characters that should not be included in an input.