Proper Case Function in C#

I found this proper case function but had no way to comment on how to improve it so I will post it in my blog. There are times when you want to capitalize words with hyphens such as capitalizing the S in Ann-Smith. I modified the function as follows:

public static string ProperCase(string stringInput)

{

    System.Text.StringBuilder sb = new System.Text.StringBuilder();

    bool fEmptyBefore = true;

    foreach (char ch in stringInput)

    {

        char chThis = ch;

        if (Char.IsWhiteSpace(chThis))

            fEmptyBefore = true;

        else if (Char.IsPunctuation(chThis))

            fEmptyBefore = true; // treat punctuations as spaces

        else

        {

            if (Char.IsLetter(chThis) && fEmptyBefore)

                chThis = Char.ToUpper(chThis);

            else

                chThis = Char.ToLower(chThis);

            fEmptyBefore = false;

        }

        sb.Append(chThis);

    }

    return sb.ToString();

} 

As you can see, the section with the comment "treat punctuations as spaces" was added to handle these situations.

Other Possible Improvements: Handling words such as McDonald.


Adiel