Manipulating a String: Removing special characters - Change all accented letters to non accented

Question

I'm using asp.net 4 and c#.

I have a string that can contains:

• Special Characters, like: !"£$%&/()/#
• Accented letters, like: àòèù
• Empty spaces, like: " "(1 consecutive or more),

Example string:

#Hi this          is  rèally/ special strìng!!!

I would like to:

a) Remove all Special Characters, like:

Hi this          is  rèally special strìng

b) Convert all Accented letters to NON Accented letters, like:

Hi this          is  really special string

c) Remove all Empty spaces and replace theme with a dash (-), like:

Hi-this-is-really-special-string

My aim is to creating a string suitable for URL path for better SEO.

Any idea how to do it with Regular Expression or another techniques?

Thanks for your help on this!

Answer 1

Similar to mathieu's answer, but more custom made for you requirements. This solution first strips special characters and diacritics from the input string, and then replaces whitespace with dashes:

string s = "#Hi this          is  rèally/ special strìng!!!";
string normalized = s.Normalize(NormalizationForm.FormD);


StringBuilder resultBuilder = new StringBuilder();
foreach (var character in normalized)
{
    UnicodeCategory category = CharUnicodeInfo.GetUnicodeCategory(character);
    if (category == UnicodeCategory.LowercaseLetter
        || category == UnicodeCategory.UppercaseLetter
        || category == UnicodeCategory.SpaceSeparator)
        resultBuilder.Append(character);
}
string result = Regex.Replace(resultBuilder.ToString(), @"\s+", "-");

See it in action at ideone.com.

Answer 2

You should have a look a this answer : Ignoring accented letters in string comparison

Code here :

static string RemoveDiacritics(string sIn)
{
  string sFormD = sIn.Normalize(NormalizationForm.FormD);
  StringBuilder sb = new StringBuilder();

  foreach (char ch in sFormD)
  {
    UnicodeCategory uc = CharUnicodeInfo.GetUnicodeCategory(ch);
    if (uc != UnicodeCategory.NonSpacingMark)
    {
      sb.Append(ch);
    }
  }

  return (sb.ToString().Normalize(NormalizationForm.FormC));
}