如何检查按钮是否被点击？

I used a GridLayout to arrange the board and have 9 buttons to represent the individual game squares. There is going to be an array to hold each of the buttons unless there is an efficient alternative to handling the group of buttons. If the button is clicked, the square should change to an X or O. Any help on implementing the design would be helpful, although I am not looking for the entire solution. I used a GridLayout to arrange the board and ha