我是JAVA新手 在练习SpringLayout布局时 放在SpringLayout布局容中的控件不会显示 找不出问题 请高手帮忙 小弟在此谢过下面是我写的程序package buju.tanhuang;import javax.swing.*;public class Lianxi extends JFrame
{ /**
* @param args
*/
private JButton j1=new JButton("弹簧布局");
private JPanel jpa=new JPanel();
private SpringLayout ss1=new SpringLayout();
public Lianxi()
{
jpa.setLayout(ss1);
jpa.add(j1);
Spring a1=Spring.constant(0,100,400);
ss1.putConstraint(SpringLayout.WEST,j1,20,SpringLayout.WEST,jpa);
ss1.putConstraint(SpringLayout.EAST,j1,20,SpringLayout.EAST,jpa);
ss1.putConstraint(SpringLayout.NORTH,j1,20,SpringLayout.NORTH,jpa);
ss1.putConstraint(SpringLayout.WEST, j1, a1, SpringLayout.EAST, j1);
//jpa.revalidate();
this.add(jpa);
this.setTitle("弹簧布局练习");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setBounds(200, 200, 200, 100);
this.setVisible(true);
}
public static void main(String[] args)
{
// TODO Auto-generated method stub
new Lianxi();
}}
{ /**
* @param args
*/
private JButton j1=new JButton("弹簧布局");
private JPanel jpa=new JPanel();
private SpringLayout ss1=new SpringLayout();
public Lianxi()
{
jpa.setLayout(ss1);
jpa.add(j1);
Spring a1=Spring.constant(0,100,400);
ss1.putConstraint(SpringLayout.WEST,j1,20,SpringLayout.WEST,jpa);
ss1.putConstraint(SpringLayout.EAST,j1,20,SpringLayout.EAST,jpa);
ss1.putConstraint(SpringLayout.NORTH,j1,20,SpringLayout.NORTH,jpa);
ss1.putConstraint(SpringLayout.WEST, j1, a1, SpringLayout.EAST, j1);
//jpa.revalidate();
this.add(jpa);
this.setTitle("弹簧布局练习");
this.setDefaultCloseOperation(EXIT_ON_CLOSE);
this.setBounds(200, 200, 200, 100);
this.setVisible(true);
}
public static void main(String[] args)
{
// TODO Auto-generated method stub
new Lianxi();
}}
解决方案 »
免费领取超大流量手机卡,每月29元包185G流量+100分钟通话, 中国电信官方发货