Java 使用JSpinner stateChanged方法更新JOptionPane中的消息

我制作了一个包含JSpinner组件的JOptionPane。我有一个名为skillMessage的字符串，它将是JOptionPane中显示的消息。我结合了我在网上所做的研究，制作了这样一个选项窗格（带有消息和微调器，以及被覆盖的stateChanged方法）。这是我的代码：

skillMessage = "Current skill level: " + currLevel + "\n";

if (skillPoint > 0) {
    skillMessage += "Do you want to upgrade this skill to level " + (currLevel + 1)  + "?\n";
} else {
    skillMessage += "You do not have enough skill point to upgrade this skill!\n";
}

skillMessage += "Cost: 1 skill point\nYou have: " + skillPoint + " skill point(s) left";

if (skillPoint > 0) {
    Object[] options = {"Upgrade", "Cancel"};

    JSpinner spinner = new JSpinner(new SpinnerNumberModel(currLevel, currLevel, maxLevel, 1));
    JComponent comp = spinner.getEditor();
    JFormattedTextField field = (JFormattedTextField)comp.getComponent(0);
    DefaultFormatter formatter = (DefaultFormatter)field.getFormatter();
    formatter.setCommitsOnValidEdit(true);
    ((JSpinner.DefaultEditor)comp).getTextField().setEditable(false);
    ((JSpinner.DefaultEditor)comp).getTextField().setFocusable(false);

    spinner.addChangeListener(new ChangeListener() {
        @Override
        public void stateChanged(ChangeEvent ce) {
            int valueChanged = (Integer)spinner.getValue() - currLevel;
            skillMessage = "Current skill level: " + spinner.getValue() + "\n";

            if ((skillPoint - valueChanged) > 0) {
                skillMessage += "Do you want to upgrade this skill to level " + (currLevel + 1)  + "?\n";
            } else {
                skillMessage += "You do not have enough skill point to upgrade this skill!\n";
            }

            skillMessage += "Cost: 1 skill point\nYou have: " + (skillPoint - valueChanged) + " skill point(s) left";
            repaint();
        }
    });

    if (JOptionPane.showOptionDialog(null, new Object[] {skillMessage, spinner}, "Upgrade Skill", 1, 3, null, options, options[0]) == 0) {
        if ((skillPoint - (Integer)spinner.getValue() - currLevel) >= 0) {
            currLevel++;
            JOptionPane.showMessageDialog(null, "You've successfully upgraded this skill to level " + currLevel);
        } else {
            JOptionPane.showMessageDialog(null, "You do not have enough skill point!");
        }
    }
}

---

我现在要做的是，每次调用微调器的stateChanged方法时，都要使JopOptions窗格中的skillMessage得到“更新”。重新粉刷似乎不管用。提前谢谢

您实际上并没有在

作业窗格

上触发重新绘制，即使您触发了，我也不确定它是否会更新

更好的解决方案是将您试图执行的功能封装到它自己的类/组件中，这样，您就可以控制视图本身，并可以根据需要更新组件

例如：

public class SkillPane extends JPanel {

    private JSpinner spinner;
    private JLabel[] messages;
    private int skillPoints;
    private int currLevel;

    public SkillPane(final int currLevel, final int maxLevel, final int skillPoint) {
        spinner = new JSpinner(new SpinnerNumberModel(currLevel, currLevel, maxLevel, 1));
        this.skillPoints = skillPoint;
        this.currLevel = currLevel;

        messages = new JLabel[]{new JLabel(), new JLabel(), new JLabel()};
        updateMessages();

        setBorder(new EmptyBorder(4, 4, 4, 4));
        setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(4, 4, 4, 4);
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        gbc.anchor = GridBagConstraints.LINE_START;
        add(messages[0], gbc);
        add(messages[1], gbc);
        add(messages[2], gbc);
        add(spinner, gbc);

        spinner.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent ce) {
                updateMessages();
            }
        });
    }

    public int getValue() {
        return (int) spinner.getValue();
    }

    public void updateMessages() {
        int valueChanged = (Integer) spinner.getValue() - currLevel;
        messages[0].setText("Current skill level: " + spinner.getValue());

        if ((skillPoints - valueChanged) > 0) {
            messages[1].setText("Do you want to upgrade this skill to level " + (currLevel + 1) + "?");
        } else {
            messages[1].setText("You do not have enough skill point to upgrade this skill!");
        }

        messages[2].setText("Cost: 1 skill point\nYou have: " + (skillPoints - valueChanged) + " skill point(s) left");
    }

}

注意：我最初的设计只有一个标签，并使用HTML来格式化文本，但我发现，随着对话框的不断中断，您也可以使用不可编辑的

JTextArea

或类似组件来生成类似的效果

你可以用类似于

    int skillPoint = 10;
    int currLevel = 0;

    Object[] options = {"Upgrade", "Cancel"};
    SkillPane pane = new SkillPane(currLevel, 100, skillPoint);

    if (JOptionPane.showOptionDialog(null, pane, "Upgrade Skill", 1, 3, null, options, options[0]) == 0) {
        int value = pane.getValue();

        if ((skillPoint - value - currLevel) >= 0) {
            currLevel++;
            JOptionPane.showMessageDialog(null, "You've successfully upgraded this skill to level " + currLevel);
        } else {
            JOptionPane.showMessageDialog(null, "You do not have enough skill point!");
        }
    }

---

实际上，您没有在

作业窗格

上触发重新绘制，即使触发了，我也不确定它是否会更新

更好的解决方案是将您试图执行的功能封装到它自己的类/组件中，这样，您就可以控制视图本身，并可以根据需要更新组件

例如：

public class SkillPane extends JPanel {

    private JSpinner spinner;
    private JLabel[] messages;
    private int skillPoints;
    private int currLevel;

    public SkillPane(final int currLevel, final int maxLevel, final int skillPoint) {
        spinner = new JSpinner(new SpinnerNumberModel(currLevel, currLevel, maxLevel, 1));
        this.skillPoints = skillPoint;
        this.currLevel = currLevel;

        messages = new JLabel[]{new JLabel(), new JLabel(), new JLabel()};
        updateMessages();

        setBorder(new EmptyBorder(4, 4, 4, 4));
        setLayout(new GridBagLayout());
        GridBagConstraints gbc = new GridBagConstraints();
        gbc.insets = new Insets(4, 4, 4, 4);
        gbc.gridwidth = GridBagConstraints.REMAINDER;
        gbc.anchor = GridBagConstraints.LINE_START;
        add(messages[0], gbc);
        add(messages[1], gbc);
        add(messages[2], gbc);
        add(spinner, gbc);

        spinner.addChangeListener(new ChangeListener() {
            @Override
            public void stateChanged(ChangeEvent ce) {
                updateMessages();
            }
        });
    }

    public int getValue() {
        return (int) spinner.getValue();
    }

    public void updateMessages() {
        int valueChanged = (Integer) spinner.getValue() - currLevel;
        messages[0].setText("Current skill level: " + spinner.getValue());

        if ((skillPoints - valueChanged) > 0) {
            messages[1].setText("Do you want to upgrade this skill to level " + (currLevel + 1) + "?");
        } else {
            messages[1].setText("You do not have enough skill point to upgrade this skill!");
        }

        messages[2].setText("Cost: 1 skill point\nYou have: " + (skillPoints - valueChanged) + " skill point(s) left");
    }

}

注意：我最初的设计只有一个标签，并使用HTML来格式化文本，但我发现，随着对话框的不断中断，您也可以使用不可编辑的

JTextArea

或类似组件来生成类似的效果

你可以用类似于

    int skillPoint = 10;
    int currLevel = 0;

    Object[] options = {"Upgrade", "Cancel"};
    SkillPane pane = new SkillPane(currLevel, 100, skillPoint);

    if (JOptionPane.showOptionDialog(null, pane, "Upgrade Skill", 1, 3, null, options, options[0]) == 0) {
        int value = pane.getValue();

        if ((skillPoint - value - currLevel) >= 0) {
            currLevel++;
            JOptionPane.showMessageDialog(null, "You've successfully upgraded this skill to level " + currLevel);
        } else {
            JOptionPane.showMessageDialog(null, "You do not have enough skill point!");
        }
    }

---

问题是，您真正重新绘制的是什么-提示，这不是

JOptionPane

，我的建议是将消息和微调器包装到一个自包含的类中，该类从

JPanel

扩展，然后将消息输出到

JLabel

@MadProgrammer是，我必须承认，我有点急切地想把repait（）放在那里，我想它是在重新绘制整个画面，而不是JOptionPane本身。如果我按照你的建议，将JLabel（用于放置输出消息）放在JOptionPane中，我是否能够使用微调器的stateChanged方法“更新”它？问题是，你真正要重新绘制什么-提示，它不是

JOptionPane

，我的建议是将消息和微调器包装到一个自包含类中，该类从

JPanel

扩展而来，然后将消息输出到

JLabel

@MadProgrammer是的，我必须承认，我有点急于将repaint（）放在那里，我认为这是在重新绘制整个框架，而不是JOptionPane本身。如果我按照你的建议，将JLabel（用于放置输出消息）放在JOptionPane中，我是否能够使用微调器的stateChanged方法“更新”它？谢谢！这似乎是正确的！我最终使用了不可编辑的JTextPane，因为我希望能够修改某些文本的颜色。仅供参考

JLabel

支持

HTML

rendering；）非常感谢。这似乎是正确的！我最终使用了不可编辑的JTextPane，因为我希望能够修改某些文本的颜色。仅供参考

JLabel

支持

HTML

rendering；）