Swing滚动条重写

Swing滚动条重写

摘自：https://blog.csdn.net/qq_40064948/article/details/81738191

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 Swing滚动条重写
 2018年08月16日 11:17:20
 阅读数：3
 package com.bjsxt.view.ui;

 import java.awt.AlphaComposite;
 import java.awt.Color;
 import java.awt.Graphics;
 import java.awt.Graphics2D;
 import java.awt.Rectangle;

 import javax.swing.ImageIcon;
 import javax.swing.JButton;
 import javax.swing.JComponent;
 import javax.swing.plaf.basic.BasicScrollBarUI;

 /**
  * 自定义滚动条
  * @author Silly
  *
  */
 public class MyScrollBarUI extends BasicScrollBarUI  {  

     @Override
     protected void configureScrollBarColors() {
         // 滑道
         trackColor = Color.WHITE;
     }

     @Override
     protected void paintTrack(Graphics g, JComponent c, Rectangle trackBounds) {
         super.paintTrack(g, c, trackBounds);
     }

     //把手
     @Override
     protected void paintThumb(Graphics g, JComponent c, Rectangle thumbBounds) {
         // 把绘制区的x，y点坐标定义为坐标系的原点，这句一定一定要加上，不然拖动就失效了
         g.translate(thumbBounds.x, thumbBounds.y);
         // 设置把手颜色
         g.setColor(new Color(200,200,200));
         // 画一个圆角矩形，前4个参数为坐标和宽高，后面两个参数用于控制角落的圆角弧度
         g.drawRoundRect(5, 0, 6, thumbBounds.height-1, 5, 5);
         Graphics2D g2 = (Graphics2D) g;
         //消除锯齿------------没有任何意义注掉
 //        RenderingHints rh = new RenderingHints(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
 //        g2.addRenderingHints(rh);
         // 半透明
         g2.setComposite(AlphaComposite.getInstance(AlphaComposite.SRC_OVER, 0.5f));
         // 设置填充颜色，这里设置了渐变，由下往上 ------------不好看注掉
 //        g2.setPaint(new GradientPaint(c.getWidth() / 2, 1, Color.GRAY, c.getWidth() / 2, c.getHeight(), Color.GRAY));
         // 填充圆角矩形
         g2.fillRoundRect(5, 0, 6, thumbBounds.height-1, 5, 5);
     }

     @Override
     protected JButton createIncreaseButton(int orientation) {
         JButton button = new JButton(produceImage("down.png"));
         button.setBorder(null);
         return button;
     }

     @Override
     protected JButton createDecreaseButton(int orientation) {
         JButton button = new JButton(produceImage("up.png"));
         button.setBorder(null);
         return button;
     }

     /**
      * 获取图片
      * @param name 图片名称
      * @return
      */
     private ImageIcon produceImage(String name) {
         ImageIcon backImage = new ImageIcon("img\\scroll\\"+name);
         return backImage;
     }

 }

 设置方式：

     JScrollPane friendScro = new JScrollPane(tree);
     friendScro.getVerticalScrollBar().setUI(new MyScrollBarUI());
 来自一个喜欢编程的小姐姐 >.<

 客官~有缘再见!