C#开发井字棋游戏如何防止玩家覆盖已填充的棋盘位置

核心修改逻辑 #

你当前的代码仅对玩家输入做了数值范围校验，缺少对目标位置是否已被填充的判断，按以下步骤修改即可实现需求：

1. 新增位置占用校验方法 #

在Board类中添加公共校验方法，将玩家输入的1-9位编号转换为二维数组坐标后判断是否为空：

public bool IsPositionEmpty(int pos)
{
    int row = (pos - 1) / 3;
    int col = (pos - 1) % 3;
    // char类型默认值为\0，代表位置未被填充
    return gamee[row, col] == '\0';
}

2. 优化玩家输入校验逻辑 #

修改Player类中的GetPlayer1、GetPlayer2方法，新增位置占用校验规则，同时修正原有范围校验的边界错误（原规则允许输入0，实际可选位置为1-9）：

修改后的GetPlayer1方法

public int GetPlayer1(Board board)
{
    while (true)
    {
        Console.Write("Player 1,chose from the above numbers to Print X on the specific position: ");
        player1 = int.Parse(Console.ReadLine());

        if (player1 < 1 || player1 > 9)
        {
            Console.WriteLine("Try again and enter a valid number (1-9)");
        }
        else if (!board.IsPositionEmpty(player1))
        {
            Console.WriteLine("This position is already occupied, please choose another one");
        }
        else
        {
            break;
        }
    }
    return player1;
}

修改后的GetPlayer2方法

public int GetPlayer2(Board board)
{
    while (true)
    {
        Console.Write("Player 2,chose from the above numbers to Print O on the specific position: ");
        player2 = int.Parse(Console.ReadLine());

        if (player2 < 1 || player2 > 9)
        {
            Console.WriteLine("Try again and enter a valid number (1-9)");
        }
        else if (!board.IsPositionEmpty(player2))
        {
            Console.WriteLine("This position is already occupied, please choose another one");
        }
        else
        {
            break;
        }
    }
    return player2;
}

3. 可选优化 #

你原有Main方法中的循环仅执行6次，且胜负判定后未终止流程，可修改为无限循环，触发胜负/平局条件后直接跳出：

static void Main(string[] args)
{
    Board board = new Board();
    Board.BoardNumbers();
    while(true)
    {
        if(WinCondition.IsDraw(board))
        {
            Console.WriteLine("Draw");
            break;
        }
        board.GetStateOfFirstPlayer(board);
        board.PrintBoard();
        if(WinCondition.IsFirstPlayerWon(board))
        {
            Console.WriteLine("First Player Won");
            break;
        }
        if(WinCondition.IsDraw(board))
        {
            Console.WriteLine("Draw");
            break;
        }
        board.GetStateOfSecondPlayer(board);
        board.PrintBoard();
        if (WinCondition.IsSecondPlayerWon(board))
        {
            Console.WriteLine("Second Player Won");
            break;
        }
    }
}

内容的提问来源于stack exchange，提问作者Amr Ali