Question

我有一个 Java 按钮可以打开 JColorChooser 对话框。我希望根据对话框中选中的颜色更改按钮的颜色。我尝试了调用此按钮的设置背景颜色() 方法, 但对于我来说它没有效果( 按钮在 Winsows 的 JTool Bar 上 ) 。另外, < href=" https:// stackoverflow. com/ questions/6256483/ how- to- set- the- button- color- a- jutton- noback- glocol” > 这个 < a > 问题表明更改按钮背景不是独立于平台的。

这个问题的答案或许是首先不使用按钮。因此,我的问题是: 在 Java 中是否有一种方法显示“ 颜色采集器” 控制, 来反映所选的颜色? 比如 MS Paint 将如何显示“ 颜色填充” 按钮上所选的颜色。

Answer 1

您有几个选项 :

如 @mKorbel s

按下按钮 opaque ,正如 @Robin

修改包含此按钮的面板的背景, 如 < a href=> 显示的“ https:// stackoverflow.com/ a/ 34/ 24431/ 230513> 。

执行 Icon 接口,并对(或接近)您的按钮应用实例,如显示这里。

Answer 2

从上下文中无法确定, 您的意思是 < a href=" http://docs. oracle. com/javase/tuative/ uiswing/ uiswing/ partments/ colorchooser. html " rel= "nofoln noreferr" > JCololorChooser 或其 Jconconconents 的



""https://i.sstatic.net/HnSDR.jpg" alt="此处的内置图像描述"/ >

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Component;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;

import javax.swing.ComboBoxEditor;
import javax.swing.DefaultListCellRenderer;
import javax.swing.JButton;
import javax.swing.JColorChooser;
import javax.swing.JComboBox;
import javax.swing.JFrame;
import javax.swing.JLabel;
import javax.swing.JList;
import javax.swing.ListCellRenderer;
import javax.swing.border.LineBorder;
import javax.swing.event.EventListenerList;

class ColorComboBoxEditor implements ComboBoxEditor {

    final protected JButton editor;
    private EventListenerList listenerList = new EventListenerList();

    ColorComboBoxEditor(Color initialColor) {
        editor = new JButton("");
        editor.setBackground(initialColor);
        ActionListener actionListener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent e) {
                Color currentBackground = editor.getBackground();
                Color color = JColorChooser.showDialog(editor, "Color Chooser", currentBackground);
                if ((color != null) && (currentBackground != color)) {
                    editor.setBackground(color);
                    fireActionEvent(color);
                }
            }
        };
        editor.addActionListener(actionListener);
    }

    @Override
    public void addActionListener(ActionListener l) {
        listenerList.add(ActionListener.class, l);
    }

    @Override
    public Component getEditorComponent() {
        return editor;
    }

    @Override
    public Object getItem() {
        return editor.getBackground();
    }

    @Override
    public void removeActionListener(ActionListener l) {
        listenerList.remove(ActionListener.class, l);
    }

    @Override
    public void selectAll() {
    }

    @Override
    public void setItem(Object newValue) {
        if (newValue instanceof Color) {
            Color color = (Color) newValue;
            editor.setBackground(color);
        } else {
            try {
                Color color = Color.decode(newValue.toString());
                editor.setBackground(color);
            } catch (NumberFormatException e) {
            }
        }
    }

    protected void fireActionEvent(Color color) {
        Object listeners[] = listenerList.getListenerList();
        for (int i = listeners.length - 2; i >= 0; i -= 2) {
            if (listeners[i] == ActionListener.class) {
                ActionEvent actionEvent = new ActionEvent(editor, ActionEvent.ACTION_PERFORMED, color.toString());
                ((ActionListener) listeners[i + 1]).actionPerformed(actionEvent);
            }
        }
    }
}

class ColorCellRenderer implements ListCellRenderer {

    private DefaultListCellRenderer defaultRenderer = new DefaultListCellRenderer();
    private final static Dimension preferredSize = new Dimension(0, 20);

    @Override
    public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) {
        JLabel renderer = (JLabel) defaultRenderer.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus);
        if (value instanceof Color) {
            renderer.setBackground((Color) value);
        }
        if (cellHasFocus || isSelected) {
            renderer.setBorder(new LineBorder(Color.DARK_GRAY));
        } else {
            renderer.setBorder(null);
        }
        renderer.setPreferredSize(preferredSize);
        return renderer;
    }
}

class ColorComboBoxEditorRendererDemo {

    public ColorComboBoxEditorRendererDemo() {
        Color colors[] = {Color.BLACK, Color.BLUE, Color.GREEN, Color.RED, Color.WHITE, Color.YELLOW};
        JFrame frame = new JFrame("Color JComboBox");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        final JComboBox comboBox = new JComboBox(colors);
        comboBox.setEditable(true);
        comboBox.setRenderer(new ColorCellRenderer());
        Color color = (Color) comboBox.getSelectedItem();
        ComboBoxEditor editor = new ColorComboBoxEditor(color);
        comboBox.setEditor(editor);
        frame.add(comboBox, BorderLayout.NORTH);
        final JLabel label = new JLabel();
        label.setOpaque(true);
        label.setBackground((Color) comboBox.getSelectedItem());
        frame.add(label, BorderLayout.CENTER);
        ActionListener actionListener = new ActionListener() {

            @Override
            public void actionPerformed(ActionEvent actionEvent) {
                Color selectedColor = (Color) comboBox.getSelectedItem();
                label.setBackground(selectedColor);
            }
        };
        comboBox.addActionListener(actionListener);
        frame.setSize(300, 200);
        frame.setVisible(true);
    }

    public static void main(String args[]) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                ColorComboBoxEditorRendererDemo colorComboBoxEditorRendererDemo = new ColorComboBoxEditorRendererDemo();
            }
        });
    } 
}

Answer 3

从,颜色选择按钮类:

shows current selected color
opens a JColorChooser dialog when pressed
fires events when a color is selected

友情链接