swing组件如何刷新？

Question

你可以用pl.updateUI()来更新。
Swing是no-thread-safe的
因此，只能在event-dispatching-thread中对Swing Component进行操作

Answer 1

如果你的p1.add(new JLabel("aaa"));是在frame.setVisible(true);之后才添加的，那么你需要先使p1作废，然后再重新布局就可以显示出新的内容。
p1.invalidate();
p1.validate();
<------ 树欲静而风不止 ------>

Answer 2

repaint()
invalidate();
updateUI();
换着试试.

Answer 3

在一个JFrame中调用这个dialog，注意，basicPane已经加了东西，但由于tabPane加basicPane在前，加basicNorthPane在后，所以没有正确显示
import javax.swing.*;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.*;/**
 * Created by IntelliJ IDEA.
 * User: purples
 * Date: 2003-12-23
 * Time: 16:42:59
 * To change this template use Options | File Templates.
 */
//main panel show in NodeModifyDlg to modify node,or it could use to instead node add panel
public class NodeModifyDlg extends JDialog implements ActionListener{    public void actionPerformed(ActionEvent event){
        String command = event.getActionCommand();
        if(command.equals("close")){
            this.dispose();
            if(DEBUG == true){
                System.out.println("close");
            }
        }
    }    public NodeModifyDlg(Frame frame, boolean model, boolean isAdd){
        super(frame, model);
        init(true, isAdd);
    }
    //default is model,not node add dialog
    public NodeModifyDlg(Frame frame){
        super(frame, true);
        init(false, false);
    }    public NodeModifyDlg(Dialog dialog, boolean model, boolean isAdd){
        super(dialog, model);
        init(false, isAdd);
    }    public NodeModifyDlg(Dialog dialog){
        super(dialog,true);
        init(false, false);
    }    protected void init(boolean debug, boolean isAdd){
        DEBUG = debug;
        this.isAdd = isAdd;
        jbinit();
    }    //init the GUI
    private void jbinit(){
        Container c = this.getContentPane();
        //datePane draw
        datePane = new JPanel();
        datePane.setLayout(new FlowLayout(FlowLayout.LEFT,10,5));
        timeLabel = new JLabel("Register Date:"+new java.util.Date());   //todo: need getData() to replace
        updateLabel = new JLabel("Update Date:");//need getUpdateData() to add
        datePane.add(timeLabel);
        datePane.add(updateLabel);
        //datePane finished
                 //tabPane draw
        tabPane = new JTabbedPane();
        tabPane.addTab("Basic info", basicPane);
        tabPane.addTab("Control info", controlPane);
        //button draw
        nodeOk = new JButton("Ok");
        nodeClose = new JButton("Close");
        nodeOk.setActionCommand("ok");
        nodeClose.setActionCommand("close");
        nodeOk.addActionListener(this);
        nodeClose.addActionListener(this);
        buttonPane = new JPanel();
        buttonPane.setLayout(new FlowLayout(FlowLayout.RIGHT,10,10));
        buttonPane.add(nodeOk);
        buttonPane.add(nodeClose);
        //button draw finished        c.setLayout(new BorderLayout(10,10));
        if(isAdd == false){
            setTitle("Node Modify");
            c.add(BorderLayout.NORTH, datePane);
        }
        else{
            setTitle("Node Add");
        }
        makeTabPane();
//        tabPane.invalidate();
//        tabPane.validate();
       
        c.add(BorderLayout.CENTER,tabPane);
//        basicNorthPane.invalidate();
//        basicNorthPane.validate();
 //       basicNorthPane.repaint();
//        tabPane.updateUI();
        c.add(BorderLayout.SOUTH, buttonPane);
    }    private void makeTabPane(){
        basicPaneInit();
        controlPaneInit();
    }    private void basicPaneInit(){
        basicPane = new JPanel();
        basicNorthPane = new JPanel();
        basicNorthPane.setLayout(new FlowLayout(FlowLayout.LEFT));
        locationLabel = new JLabel("Location");
        locationComboBox = new JComboBox();
        //todo: add item to comboBox here
        basicNorthPane.add(locationLabel);
        basicNorthPane.add(locationComboBox);        basicPane.setLayout(new BorderLayout());
        basicPane.add( BorderLayout.NORTH, basicNorthPane);    }    private void controlPaneInit(){
        controlPane = new JPanel();
    }    public void setDEBUG(boolean DEBUG) {
        this.DEBUG = DEBUG;
    }    private boolean isAdd;
    private JPanel datePane;
    private JLabel timeLabel;
    private JLabel updateLabel;
    private JTabbedPane tabPane;
    private JPanel basicPane;
    private JPanel controlPane;    private JPanel basicNorthPane;
    private JPanel basicCenterPane;
    private JPanel basicEastPane;
    private JPanel basciSouthPane;    private JLabel locationLabel;
    private JComboBox locationComboBox;    private JPanel buttonPane;
    private JButton nodeOk;
    private JButton nodeClose;
    private boolean DEBUG;
}