Is there a native Proper Case string function in C#?

String s  = "yOu caN Use thIs"

s = System.Threading.Thread.CurrentThread
           .CurrentCulture.TextInfo.ToTitleCase(s.ToLower());

The main limitation I can see with this is that it's not "true" title case. i.e. In the phrase "WaR aNd peaCe", the "and" part should be lowercase in English. This method would capitalise it though.

There is a function that capitalises the first letters of words, though you should see the remarks section as it does have some limitations which may make it unsuitable for your needs.

This should work.

public static string ToTitleCase(this string strX)
{
    string[] aryWords = strX.Trim().Split(' ');

    List<string> lstLetters = new List<string>();
    List<string> lstWords = new List<string>();

    foreach (string strWord in aryWords)
    {
        int iLCount = 0;
        foreach (char chrLetter in strWord.Trim())
        {
            if (iLCount == 0)
            {
                lstLetters.Add(chrLetter.ToString().ToUpper());
            }
            else
            {
                lstLetters.Add(chrLetter.ToString().ToLower());
            }
            iLCount++;
        }
        lstWords.Add(string.Join("", lstLetters));
        lstLetters.Clear();
    }

    string strNewString = string.Join(" ", lstWords);

    return strNewString;
}