Is there a case insensitive string replace in .Net without using Regex?

Question

I recently had to perform some string replacements in .net and found myself developing a regular expression replacement function for this purpose. After getting it to work I

Answer 1

I know of no canned instance in the framework, but here's another extension method version with a minimal amount of statements (although maybe not the fastest), for fun. More versions of replacement functions are posted at http://www.codeproject.com/KB/string/fastestcscaseinsstringrep.aspx and "Is there an alternative to string.Replace that is case-insensitive?" as well.

public static string ReplaceIgnoreCase(this string alterableString, string oldValue, string newValue){
    if(alterableString == null) return null;
    for(
        int i = alterableString.IndexOf(oldValue, System.StringComparison.CurrentCultureIgnoreCase);
        i > -1;
        i = alterableString.IndexOf(oldValue, i+newValue.Length, System.StringComparison.CurrentCultureIgnoreCase)
    ) alterableString =
        alterableString.Substring(0, i)
        +newValue
        +alterableString.Substring(i+oldValue.Length)
    ;
    return alterableString;
}