java - 如何在其他类中使用 JColorChooser 给定颜色？

Question

我学习 Java 才几周时间，所以请记住这一点..我自己已经成功解决了许多问题，直到这个:

我想要实现的是在选项卡式 View 中使用 JComponent，以便在一个选项卡中您可以选择一种颜色(我的 println 显示它实际上获得了 sRGB 值)。然后在另一个类中我应该能够获取这个值并将其用于为 JPanel 着色。我可以只传递 Color 对象吗？或者实现的最佳方法是什么？我在这里尝试的效果不太好。抱歉，代码很乱 - 我是新手......这是颜色选择器的主要部分:

public class Colors extends JPanel implements ChangeListener {

    private JColorChooser jcc = null;
    protected JLabel title;
    static Color newColor;

    public Colors() {
        super(new BorderLayout());

        //Set up the banner at the top of the window
        title = new JLabel();

        //Set up color chooser for setting text color
        jcc = new JColorChooser(title.getForeground());
        jcc.getSelectionModel().addChangeListener(this);
        jcc.setBorder(BorderFactory.createTitledBorder(
                "Choose New Color"));

        AbstractColorChooserPanel[] panels=jcc.getChooserPanels();
        for(AbstractColorChooserPanel p:panels) {
            String displayName = p.getDisplayName();
            switch (displayName) {
                case "HSV":
                    jcc.removeChooserPanel(p);
                    break;
                case "HSL":
                    jcc.removeChooserPanel(p);
                    break;
                case "CMYK":
                    jcc.removeChooserPanel(p);
                    break;
                case "RGB":
                    jcc.removeChooserPanel(p);
                    break;
            }
        }
        add(jcc, BorderLayout.PAGE_END);
    }



    public void stateChanged(ChangeEvent e) {
        Color newColor = jcc.getColor();
        title.setForeground(newColor);
        System.out.println("color = " + newColor);
    }

    public static Color getNewCol() {
        System.out.println("this now =" + newColor);
        return newColor;
    }

    public static Component createAndShowGUI() {
        //Create and set up the window.
        JFrame frame = new JFrame("Color Selector");
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);

        //Create and set up the content pane.
        JComponent newContentPane = new Colors();
        return newContentPane;

    }
}

然后我尝试以这种方式获取 Main.Java 类中所选的颜色(这可能是错误的)。我还注意到该值似乎始终保持为空 - 可能我以错误的方式实例化(值丢失了？)

a.addActionListener(new ActionListener() {
            @Override
            public void actionPerformed(ActionEvent e) {
                System.out.println("Click add");
                value++;

                if (value < 21) {


                    JButton jb1 = new JButton();

                    //How to get the COLOR from the JColorChooser class?
                    Color box = Colors.getNewCol();

                    jb1.setBackground(box);
                    jb1.setOpaque(true);

                    //FOR TEST ONLY jb1.setBackground(Color.BLUE);
                    panel.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
                    panel.add(jb1);
                    panel.setVisible(true);

                    //window.add(paneeli);

                    window.pack();

                    d = new Dimension(700, 500);
                    window.setSize(d);

可能答案太明显了，但我现在看不到。

Answer 1

我会获取你的静态 newColor 变量并使其成为非静态的。在我的 ChangeListener 中，我将触发 JPanel 固有的 PropertyChangeSupport，以便可以通知监听器。关键是使用观察者设计模式——例如:

import java.awt.BorderLayout;
import java.awt.Color;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import javax.swing.*;
import javax.swing.event.*;

@SuppressWarnings("serial")
public class TestColors extends JPanel {
    private JTabbedPane tabbedPane = new JTabbedPane();
    private Colors colors = new Colors();
    private JPanel colorDisplayPanel = new JPanel();

    public TestColors() {
        tabbedPane.add("Colors", colors);
        tabbedPane.add("Color Display", colorDisplayPanel);
        setLayout(new BorderLayout());
        add(tabbedPane);

        // add a PropertyChangeListener to our Colors isntance.
        colors.addPropertyChangeListener(Colors.NEW_COLOR,
                new PropertyChangeListener() {

                    @Override
                    public void propertyChange(PropertyChangeEvent evt) {
                        Color color = (Color) evt.getNewValue();
                        colorDisplayPanel.setBackground(color);
                    }
                });
    }

    private static void createAndShowGui() {
        JFrame frame = new JFrame("TestColors");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().add(new TestColors());
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }

    public static void main(String[] args) {
        SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGui();
            }
        });
    }
}

@SuppressWarnings("serial")
class Colors extends JPanel implements ChangeListener {
    public static final String NEW_COLOR = "new color";
    private JColorChooser jcc = null;
    protected JLabel title;
    private Color newColor = null;

    public Colors() {
        super(new BorderLayout());

        // Set up the banner at the top of the window
        title = new JLabel("This is my Banner!", SwingConstants.CENTER);

        // Set up color chooser for setting text color
        jcc = new JColorChooser(title.getForeground());
        jcc.getSelectionModel().addChangeListener(this);
        jcc.setBorder(BorderFactory.createTitledBorder("Choose New Color"));

        add(jcc, BorderLayout.CENTER);
        add(title, BorderLayout.PAGE_START);
    }

    public void stateChanged(ChangeEvent e) {
        // Color newColor = jcc.getColor();
        Color oldValue = newColor;
        newColor = jcc.getColor();

        // fire a notification to the Colors JPanel's property change support
        // object. Any listeners will be notified of the color change
        firePropertyChange(NEW_COLOR, oldValue, newColor);
        title.setForeground(newColor);
    }

    public Color getNewCol() {
        System.out.println("this now =" + newColor);
        return newColor;
    }

}