java 单击了 J 按钮

Question

int buttonNum = size[0] * size[1];
        panelForButtons.setLayout(new GridLayout(size[0], size[1]));

        JButton[] buttons = new JButton[buttonNum];
        buttonsArray = buttons;

        for (int i = 0; i < buttonNum; i++) {
            buttons[i] = new JButton();
//           Change each button size
           buttons[i].setPreferredSize(new Dimension(50, 50));
            panelForButtons.add(buttons[i]);
            buttons[i].setBackground(Color.black);
            buttons[i].addActionListener(new Actions());
        }
        panelOnTheLeft.add(panelForButtons, BorderLayout.WEST);
    }
    static class Actions implements ActionListener {
        public void actionPerformed(ActionEvent e) {0


        }

我想让for循环生成的每个按钮都具有单击按钮时更改背景颜色的功能，我该怎么办？

Answer 1

假设您希望每个按钮的背景颜色在单击时更改：

我可能不会将操作 class 设为静态。

在 actionPerformed() 中，获取从 e 中单击的按钮，设置其背景颜色。

在for循环中，不要每次循环都做一个new Actions()。在循环开始之前创建一个实例，并在循环期间将其传入。

int buttonNum = size[0] * size[1];
panelForButtons.setLayout(new GridLayout(size[0], size[1]));

JButton[] buttons = new JButton[buttonNum];
buttonsArray = buttons;

// The only action handler you need
Actions myActionHandler = new Actions();

for (int i = 0; i < buttonNum; i++) {
    buttons[i] = new JButton();

    // Change each button size
    buttons[i].setPreferredSize(new Dimension(50, 50));
    buttons[i].setBackground(Color.black);
    
    // Just pass in the one we already have from above
    buttons[i].addActionListener(myActionHandler);

    panelForButtons.add(buttons[i]);
}

panelOnTheLeft.add(panelForButtons, BorderLayout.WEST);


class Actions implements ActionListener {
    public void actionPerformed(ActionEvent e) {
        // Get the button that was clicked
        JButton theButton = (JButton) e.getSource();
        // Set it's background color to white
        theButton.setBackground(Color.white);
    }
}

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