JScrollPane的视口不跟随窗口大小改变移动？？？

Question

    我写了个关于JScrollPane滚动窗口的程序,其它都实现好了.但是有个问题,就是窗口大小变大时,滚动窗口的视口一直停留在原来的界面,没有跟着滚动窗口变大而往右或者往下移动(滚动条已经出现),怎么解决这个问题???

Answer 1

好像以J开头的控件组，都不大好使…
不关是JButton，JText。楼主换个控件包吧

Answer 2

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
import javax.swing.event.ChangeEvent;
import javax.swing.event.ChangeListener;public class Test {
    JFrame frame;
    JSlider slider;
    JScrollPane jsp;
    JPanel pan;
    public Test(){
        frame=new JFrame();
        Container contentPane=frame.getContentPane();
        pan=new JPanel();
        pan.setPreferredSize(new Dimension(300,300));
        jsp=new JScrollPane(pan);
        contentPane.add(jsp);
        slider=new JSlider();
        slider.setMinimum(0);
        slider.setMaximum(400);
        slider.setValue(0);
        slider.setPaintLabels(true);
        slider.setPaintTicks(true);
        slider.setPaintTrack(true);
        slider.setMajorTickSpacing(40);
        slider.addChangeListener(new ChangeListener() {
            public void stateChanged(ChangeEvent e) {
                int value=slider.getValue();
                pan.setPreferredSize(new Dimension(300+value,300+value));
                jsp.setViewportView(pan);
                //自己设置JScrollPane的两个滚动条的值
                jsp.getHorizontalScrollBar().setValue(jsp.getHorizontalScrollBar().getMaximum());
                jsp.getVerticalScrollBar().setValue(jsp.getVerticalScrollBar().getMaximum());
            }
        });
        contentPane.add(slider,BorderLayout.SOUTH);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.pack();
        frame.setLocationRelativeTo(null);
        frame.setVisible(true);
    }
    public static void main(String[] args) {
        new Test();
    }
}