java - Java 访问 boolean 数组的方法

Question

我有以下构造函数，它定义了一个 board 并检查是否单击了三个 JButton 中的任何一个:

Timer timer = new Timer(500, this);

private boolean[][] board;
private boolean isActive = true;
private int height;
private int width;
private int multiplier = 40;

JButton button1;
JButton button2;
JButton button3;
public Board(boolean[][] board) {
    this.board = board;
    height = board.length;
    width = board[0].length;
    setBackground(Color.black);
    button1 = new JButton("Stop");
    add(button1);
    button1.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            isActive = !isActive;
            button1.setText(isActive ? "Stop" : "Start");
        }
    });
    button2 = new JButton("Random");
    add(button2);
    button2.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            this.board = randomBoard();
        }
    });
    button3 = new JButton("Clear");
    add(button3);
    button3.addActionListener(new ActionListener() {
        public void actionPerformed(ActionEvent e) {
            this.board = clearBoard();
        }
    });
}

但它返回此错误:

Exception in thread "main" java.lang.Error: Unresolved compilation problems: 
    board cannot be resolved or is not a field
    board cannot be resolved or is not a field

这是为什么呢？如何在构造函数中访问 this.board？

Answer 1

该问题是由于您尝试访问匿名内部类中的 this.board 引起的。由于没有定义 board 字段，因此会导致错误。

例如:

button2.addActionListener(new ActionListener() {
    public void actionPerformed(ActionEvent e) {
        this.board = randomBoard();
    }
});

为了能够在匿名内部类中使用 board 变量，您需要删除 this 或使用类似 Board.this.board 的内容(如果你想更明确的话)。