How to split a string while ignoring the case of the delimiter?

Question

I need to split a string let\'s say \"asdf aA asdfget aa uoiu AA\" split using \"aa\" ignoring the case. to

\"asdf \"
\"asdfget \"
\"uoiu \"

Answer 1

    public static List _Split(this string input,string[] splt)
    {
        List _Result=new List();
        foreach(string _splt in splt)
        {
            if (splt.Count() == 1)
            { 
                _Result.AddRange(Regex.Split(input, _splt, RegexOptions.IgnoreCase).ToList());
            }
            else 
            {
                List NewStr = Regex.Split(input, _splt, RegexOptions.IgnoreCase).ToList();
                foreach(string _NewStr in NewStr)
                {
                    List NewSplt = splt.ToList();
                    NewSplt.Remove(_splt);
                    return _Split(_NewStr, NewSplt.ToArray());
                }
            } 
        }
        return _Result;
    } 

then use this function as bellow

public frmThematicConversation()
{
    InitializeComponent();
    string str = "a b c d e f g h a b c f a d c b f";
    string[] splt = { "a", "b" };
    List _result = str._Split(splt);
}