当我启动我的Java swing应用程序时,我将XML文件读入DefaultTreeModel,使用模型创建一个新的JTree,将jtree添加到JScrollPane,并且Life is Good。一切工作:JTree:不会重新显示新模型
// Program initialization:
jarFilesDB = new JarFilesDB();
jarFilesDB.load(JarFilesDB.JAR_DB_FILENAME);
jtree = new JTree(jarFilesDB.getRootNode());
JScrollPane scrollPane = new JScrollPane (jtree);
contentPane.add(scrollPane, BorderLayout.CENTER);
后来,我可能需要创建一个新 XML文件,并完全重建我的模型。当我这样做时,我无法让jtree重新显示新模型。无论我得到一个空白面板,或旧的模式仍显示:
// Completely regenerate XML file and Model
jarFilesDB.mkXmlFile (sPath); // Generate new XML file
jarFilesDB.load(JarFilesDB.JAR_DB_FILENAME); // Generate new Model
每安德鲁·汤普森的要求下,我写了一个“短(尽可能)的,自包含的,正确的(没有或我不会!问这个问题)例):。
package com.rgb;
import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.border.EmptyBorder;
import javax.swing.JButton;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import javax.swing.JTree;
import javax.swing.JScrollPane;
import javax.swing.tree.*;
public class FrmMain extends JFrame {
private JPanel contentPane;
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
public void run() {
try {
FrmMain frame = new FrmMain();
frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the frame.
*/
public FrmMain() {
setTitle("HelloJTree3");
setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
setBounds(100, 100, 450, 300);
contentPane = new JPanel();
contentPane.setBorder(new EmptyBorder(5, 5, 5, 5));
contentPane.setLayout(new BorderLayout(0, 0));
setContentPane(contentPane);
JButton btnNewButton = new JButton("Click Me");
btnNewButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent arg0) {
doClick();
}
});
contentPane.add(btnNewButton, BorderLayout.NORTH);
jarFilesDB = new JarFilesDB();
jarFilesDB.load(isAlpha);
isAlpha = !isAlpha;
jtree = new JTree(jarFilesDB.getRootNode());
JScrollPane scrollPane = new JScrollPane (jtree);
contentPane.add(scrollPane, BorderLayout.CENTER);
}
private void doClick() {
jarFilesDB.load(isAlpha);
isAlpha = !isAlpha;
}
private JarFilesDB jarFilesDB;
private JTree jtree;
private boolean isAlpha = false;
}
class JarFilesDB extends DefaultTreeModel {
public JarFilesDB() {
super (null);
}
public void load (boolean isAlpha) {
if (rootNode == null)
rootNode = new DefaultMutableTreeNode("root");
else
rootNode.removeAllChildren();
String[] values;
if (isAlpha)
values = new String[] {"A", "A1", "A2", "B", "B1", "B2"};
else
values = new String[] {"10", "11", "12", "20", "21", "22"};
DefaultMutableTreeNode childNode = new DefaultMutableTreeNode (values[0]);
DefaultMutableTreeNode leafNode = new DefaultMutableTreeNode (values[1]);
childNode.add(leafNode);
leafNode = new DefaultMutableTreeNode (values[2]);
childNode.add(leafNode);
rootNode.add(childNode);
childNode = new DefaultMutableTreeNode (values[3]);
leafNode = new DefaultMutableTreeNode (values[4]);
childNode.add(leafNode);
leafNode = new DefaultMutableTreeNode (values[5]);
childNode.add(leafNode);
rootNode.add(childNode);
}
public TreeNode getRootNode() {
return rootNode;
}
private DefaultMutableTreeNode rootNode = null;
}
为了更好地提供帮助,请发布[SSCCE](http://sscce.org/)。 – 2012-07-19 03:31:05
为什么不使用'jtree.setModel(jarFilesDB);'当初始化树时? – tenorsax 2012-07-19 03:47:07
@Max - 类jarFilesDB继承自DefaultTreeModel。我最初不需要“setModel()”,因为我只是使用模型的根节点作为jtree的构造函数。您删除的回复是正确的:我*不应该*需要removeAll()或setModel()。任何建议肯定会被赞赏:) Thanx提前... – paulsm4 2012-07-19 05:02:47