private async void B_Click(object sender, EventArgs e)
{
var button = sender as Button;
int index = (int)button.Tag;
if (_game.IsValidMove(index))
{
button.Text = _game.CurrentPlayer == 1 ? "X" : "O";
if (_game.PerformMove(index))
{
await DoComputerMove(index);
}
CheckGameState();
}
}
