I am currently making a Tic Tac Toe game with Windows Forms. I have a list of buttons that is storing all nine buttons (which are the game field). I have an AI as well - the first part of the game will be played by a player and a machine. I want to remove the selected button from the buttons list after the player selected it. However, I get this error on that line buttons.Remove(button) : System.NullReferenceException: 'Object reference not set to an instance of an object.'
Any idea how to fix it?
private void playerChose(object sender, EventArgs e)
{
var button = (Button)sender;
currentSymbol = Symbols.X;
button.Text = currentSymbol.ToString();
button.Enabled = false;
button.BackColor = Color.FromArgb(224, 159, 62);
buttons.Remove(button);
CheckIfPlayerWon();
MachineMove.Start();
}