JTabbedPane中加入JScrollPane的问题

[zddava]

有个奇怪的JTabbedPane中加入JScrollPane的问题

public class TabbedPane extends JTabbedPane implements ChangeListener {
......

private void initUI() {
setUI(new MainTabbedPaneUI());
addChangeListener(this);

......

MyScrollPane pane = new MyScrollPane(parent);

......

addTab(" 2 ", pane );

......

}

......

}


public class MyScrollPane extends JScrollPane {

public void refreshUI() {
removeAll();

JPanel innerPanel = new JPanel();
innerPanel.setLayout(null);
innerPanel.setPreferredSize(new Dimension(1000, 800));
innerPanel.setBorder(new LineBorder(Color.BLUE, 2));

setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);

setViewportView(innerPanel);

......

JPanel panel = new JPanel();
panel.setBorder(new LineBorder(Color.WHITE, 3, true));
panel.setBounds(......);
panel.setLayout(null);

innerPanel.add(panel);
}

}


这段代码为什么JScrollPane没有滚动条，并且innerPanel的蓝色边界也没有出现。不过如果给JScrollPane打上边界到是可以看到，太奇怪了。

请教下Swing高手。

[一天zijie一夜]

顶！等待Swing高手