I created two List fields as on Login Form

private List<string> imageList = new List<string>();
private List<string> username = new List<string>();

TicTacToe tic=new TicTacToe(usernametextBox.Text,imgTextbox.Text);

What I have to do to change in the constructor of TicTacToe so i can add in someway List of usernames.

Anyway to convert string of usernametextbox to ArrayList?