如何找到jscrol旋鈕擊中底角？

Question

我想在jscroll旋鈕碰到VerticalScrollBar的底角時發出一個事件。怎麼做？

Answer 1

import javax.swing.*; 
import java.awt.*; 
import java.awt.event.AdjustmentEvent; 
import java.awt.event.AdjustmentListener; 

public class JScrollBarTest { 
    public static void main(String[] args) { 
     JFrame fr=new JFrame(); 

     JLabel l=new JLabel("test"); 
     l.setPreferredSize(new Dimension(500, 500)); 
     JScrollPane scroll=new JScrollPane(l); 
     fr.add(scroll); 
     scroll.getVerticalScrollBar().addAdjustmentListener(new AdjustmentListener() { 
      @Override 
      public void adjustmentValueChanged(AdjustmentEvent e) { 
       JScrollBar sc=scroll.getVerticalScrollBar(); 
       System.out.println(sc.getVisibleAmount()); 
       System.out.println(sc.getMaximum()); 
       System.out.println(sc.getValue()); 
       System.out.println("------"); 
       if (sc.getVisibleAmount()+sc.getValue()==sc.getMaximum()) { 
        System.out.println("Bottom event"); 
       } 
      } 
     }); 

     fr.setSize(100, 100); 
     fr.setLocationRelativeTo(null); 
     fr.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); 
     fr.setVisible(true); 
    } 
}