更改JButton的漸變色，但只有一個按鈕，並非所有

Question

我想改變JButton漸變色， 我發現這一點，http://java2everyone.blogspot.com/2009/01/set-jbutton-gradient-color.html，但我想改變梯度只有一個按鈕，並非所有的按鈕

Answer 1

你可以覆蓋JButton實例的paintComponent方法和與實施Paint接口下面類中的一個繪製其Graphics對象：

• GradientPaint。
• LinearGradientPaint
• MultipleGradientPaint
• RadialGradientPaint

---

import java.awt.Color; 
import java.awt.Dimension; 
import java.awt.FlowLayout; 
import java.awt.GradientPaint; 
import java.awt.Graphics; 
import java.awt.Graphics2D; 
import java.awt.Point; 

import javax.swing.JButton; 
import javax.swing.JFrame; 
import javax.swing.SwingUtilities; 

public final class JGradientButtonDemo { 
    public static void main(String[] args) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       createAndShowGUI();   
      } 
     }); 
    } 

    private static void createAndShowGUI() { 
     final JFrame frame = new JFrame("Gradient JButton Demo"); 
     frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     frame.getContentPane().setLayout(new FlowLayout()); 
     frame.add(JGradientButton.newInstance()); 
     frame.setSize(new Dimension(300, 150)); // used for demonstration 
     //frame.pack(); 
     frame.setLocationRelativeTo(null); 
     frame.setVisible(true); 
    } 

    private static class JGradientButton extends JButton { 
     private JGradientButton() { 
      super("Gradient Button"); 
      setContentAreaFilled(false); 
      setFocusPainted(false); // used for demonstration 
     } 

     @Override 
     protected void paintComponent(Graphics g) { 
      final Graphics2D g2 = (Graphics2D) g.create(); 
      g2.setPaint(new GradientPaint(
        new Point(0, 0), 
        Color.WHITE, 
        new Point(0, getHeight()), 
        Color.PINK.darker())); 
      g2.fillRect(0, 0, getWidth(), getHeight()); 
      g2.dispose(); 

      super.paintComponent(g); 
     } 

     public static JGradientButton newInstance() { 
      return new JGradientButton(); 
     } 
    } 
} 

Answer 2

在麥格理的回答有點起色：

private static final class JGradientButton extends JButton{ 
    private JGradientButton(String text){ 
     super(text); 
     setContentAreaFilled(false); 
    } 

    @Override 
    protected void paintComponent(Graphics g){ 
     Graphics2D g2 = (Graphics2D)g.create(); 
     g2.setPaint(new GradientPaint(
       new Point(0, 0), 
       getBackground(), 
       new Point(0, getHeight()/3), 
       Color.WHITE)); 
     g2.fillRect(0, 0, getWidth(), getHeight()/3); 
     g2.setPaint(new GradientPaint(
       new Point(0, getHeight()/3), 
       Color.WHITE, 
       new Point(0, getHeight()), 
       getBackground())); 
     g2.fillRect(0, getHeight()/3, getWidth(), getHeight()); 
     g2.dispose(); 

     super.paintComponent(g); 
    } 
}