Question

Is there a library out there which I can use in my current ASP.NET app, to validate queryStrings?

Edit ~ Using Regex to look for patterns, like string, only, numeric only, string with length x,…etc

Thanks

Answer 1

Don’t know about a library, but you can use to check if the querystring exists:

if (!String.IsNullOrEmpty(Request.Querystring['foo'])) {    // check further } else {    // not there, do something else } 

If you want to use Reglar Expressions to further validate, you can create a class that accepts the string and return a boolean.

public static Boolean IsValid(String s) {     const String sRegEx = @'regex here';      Regex oRegEx = new Regex(sRegEx , RegexOptions.IgnoreCase | RegexOptions.Multiline | RegexOptions.IgnorePatternWhitespace | RegexOptions.Compiled);     MatchCollection oMatches = oRegEx.Matches(s);      return (oMatches.Count > 0) ? true : false; } 

This is a good free program to help you build the regluar expressions: Expresso