public static void Main()
string content = "Ahoj " + '\u001a' + "X" + '\u001c' + "Z";
Console.WriteLine(content);
Console.WriteLine(IsValidXmlString(content));
content = RemoveInvalidXmlChars(content);
Console.WriteLine(content);
Console.WriteLine(IsValidXmlString(content));
static string RemoveInvalidXmlChars(string text)
var validXmlChars = text.Where(ch => XmlConvert.IsXmlChar(ch)).ToArray();
return new string (validXmlChars);
static bool IsValidXmlString(string text)
XmlConvert.VerifyXmlChars(text);