大家帮忙看看这小段代码

[hyrongg]

我只想在一个窗体上放一个两个TAB叶的确PAGECONTROL,然后在第一个TAB叶上面放一个靠左的JLIST,
我的这段程序为什么JLIST总是居中?


import java.awt.*;
import java.awt.List;

import javax.swing.*;

public class SimpleTab extends JFrame{

JTabbedPane jtp;
String[] pages ={"Item1","Item2","Item3","Item4","Item5","Item6"};

public SimpleTab() {
super("General Decoder Manager");
setSize(600,400);
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
Container contents = getContentPane();
jtp = new JTabbedPane();
JPanel pnlRule = new JPanel();
pnlRule.setBackground(Color.BLUE);
JPanel pnlConfig = new JPanel();
JList RuleList = new JList(pages);
RuleList.setPreferredSize(new Dimension(200,100));
RuleList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION);
pnlRule.add(new JScrollPane(RuleList),BorderLayout.WEST);
jtp.addTab("Rule Manager",pnlRule);
jtp.addTab("GDM configure",pnlConfig);
contents.add(jtp);
setVisible(true);
}

public static void main(String[] args) {
SimpleTab simpleTab = new SimpleTab();
}
}

[huadis]

JPanel默认的是FlowLayout布局,你用的是边布局所以加上以下的句子就行了:

pnlRule.setLayout(new BorderLayout());

[viperasi]

楼上正解

[beautiful123086]

顶2，3楼的

[fengyifei11228]

1楼正解!