如何为放置在jtoolbar中的Jbutton添加渐变颜色 [英] How to add gradient color to Jbuttons placed in jtoolbar

问题描述

我正在使用netbeans平台模块来开发此桌面应用程序.我正在开发中使用netbeans中的拖放功能.

I am using netbeans platform module to develop this desktop application. I am using drag and drop facility in netbeans in the developement.

我需要创建一个只有几个按钮的工具栏.我需要为这些按钮创建渐变颜色.

I needed to create a toolbar which is having few buttons..I need to create a gradient color for these buttons.

我拖放了JToolBar，在其上拖放了JButton对象. 在按钮的属性中，我选择了一种我想要阴影的颜色.在自定义代码中，我进行了修改.

I dragged and dropped JToolBar, over it I dragged and placed JButton objects. In the properties of the button I have selected a color for which I want a shaded color. In the custom code I have modified.

jbutton = new javax.swing.Jbutton();

如下

jbutton = new javax.swing.JButton(){
    @Override
    protected void paintComponent(Graphics grphcs) {
        Graphics2D g2d = (Graphics2D) grphcs;
        g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
           RenderingHints.VALUE_ANTIALIAS_ON);
        GradientPaint gp = new GradientPaint(0, 0,
            getBackground().brighter().brighter().brighter(), 0, getHeight(),
            getBackground().darker());
         g2d.setPaint(gp);
        g2d.fillRect(0, 0, getWidth(), getHeight());
        super.paintComponent(grphcs);
    }};

当我在项目中将上述代码用于JPanel时，它可以工作，但是当我将其用于按钮时，它没有显示任何效果.

When I used the above code for a JPanel in my project it worked but it is not showing any effect when I used it for a button.

如何为工具栏中的按钮获取渐变颜色?

How to get a gradient color for a button placed in a toolbar?

推荐答案

按钮具有contentAreaFilled属性，该属性确定外观是否应绘制按钮的内容区域.当您调用super.paintComponent时，外观委托将在您所做的事情上作画.

The button has a contentAreaFilled attribute which determines if the look and feel should paint the content area of the button. When you call super.paintComponent, the look and feel delegate will paint over what you have done.

您可以将此属性设置为false，然后它应该可以工作.

You can set this property to false and it should then work.

例如...

import java.awt.Color;
import java.awt.Dimension;
import java.awt.EventQueue;
import java.awt.GradientPaint;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.GridBagLayout;
import java.awt.RenderingHints;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class GradientButtons {

    public static void main(String[] args) {
        new GradientButtons();
    }

    public GradientButtons() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new GridBagLayout());
                frame.add(new RoundButton("Click me"));
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class RoundButton extends JButton {

        public RoundButton(String text) {
            super(text);
            setBorderPainted(false);
            setContentAreaFilled(false);
            setFocusPainted(false);
            setOpaque(false);
        }

        @Override
        public Dimension getPreferredSize() {
            Dimension size = super.getPreferredSize();
            int radius = Math.max(size.width, size.height);
            size.width = radius;
            size.height = radius;
            return size;
        }

        @Override
        protected void paintComponent(Graphics g) {
            Graphics2D g2d = (Graphics2D) g;
            g2d.setRenderingHint(RenderingHints.KEY_ANTIALIASING,
                    RenderingHints.VALUE_ANTIALIAS_ON);
            GradientPaint gp = new GradientPaint(0, 0,
                    Color.RED, 0, getHeight(),
                    Color.YELLOW);
            g2d.setPaint(gp);
            g2d.fillOval(0, 0, getWidth(), getHeight());
            super.paintComponent(g);
        }

    }

}

您可能希望检查ButtonModel的armed和/或pressed状态，以便作为建议，也可以更改单击按钮时绘制按钮的方式.

You may want to check the ButtonModel's armed and/or pressed state so you can also change the way that the button is painted when clicked, as a suggestion...

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