The Solution 1 given by
Richard MacCutchan is very good.
As an alternative if you want to check whether the string contains a particular category of characters say
Punctuation
or
Numbers
etc., then the
System.Text.RegularExpressions.Regex
class can be considered to test as shown below:
string text = "Is this text, contains special chars?";
if(System.Text.RegularExpressions.Regex.IsMatch(text,@"\p{P}|\p{N}"))
Console.WriteLine ("Contains special chars");
else
Console.WriteLine ("Does not contain special chars");