请教：怎样修改JTree中每级节点前面的图标？

Question

DefaultTreeCellRenderer
这个类看看API吧

Answer 1

DefaultTreeCellRenderer的
  setLeafIcon(Icon newIcon) 
  setClosedIcon(Icon newIcon) 
  setOpenIcon(Icon newIcon)   
方法

Answer 2

DefaultTreeCellRenderer很容易实现的.
具体也忘了.你看一下那本"精通swing",书名也记不清了！呵呵电子书，那详细
祝好运！

Answer 3

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;public class TreeDemo4
{
    public TreeDemo4()
    {
        JFrame f = new JFrame("TreeDemo");
        Container contentPane = f.getContentPane();
        
        DefaultMutableTreeNode root = new DefaultMutableTreeNode("资源管理器");
        DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("我的公文包");
        DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("我的电脑");
        DefaultMutableTreeNode node3 = new DefaultMutableTreeNode("收藏夹");
        DefaultMutableTreeNode node4 = new DefaultMutableTreeNode("Readme");
        
        DefaultTreeModel treeModel = new DefaultTreeModel(root);
        treeModel.insertNodeInto(node1, root, root.getChildCount());
        treeModel.insertNodeInto(node2, root, root.getChildCount());
        treeModel.insertNodeInto(node3, root, root.getChildCount());
        treeModel.insertNodeInto(node4, root, root.getChildCount());
        
        DefaultMutableTreeNode leafnode = new 
                DefaultMutableTreeNode("公司文件");
        treeModel.insertNodeInto(leafnode, node1, node1.getChildCount());
        leafnode = new DefaultMutableTreeNode("个人信件");
        treeModel.insertNodeInto(leafnode, node1, node1.getChildCount());
        leafnode = new DefaultMutableTreeNode("私人文件");
        treeModel.insertNodeInto(leafnode, node1, node1.getChildCount());
        
        leafnode = new DefaultMutableTreeNode("本机磁盘(C:)");
        treeModel.insertNodeInto(leafnode, node2, node2.getChildCount());
        leafnode = new DefaultMutableTreeNode("本机磁盘(D:)");
        treeModel.insertNodeInto(leafnode, node2, node2.getChildCount());
        leafnode = new DefaultMutableTreeNode("本机磁盘(E:)");
        treeModel.insertNodeInto(leafnode, node2, node2.getChildCount());
        
        DefaultMutableTreeNode node31 = new DefaultMutableTreeNode("网站列表");
        treeModel.insertNodeInto(node31, node3, node3.getChildCount());
        leafnode = new DefaultMutableTreeNode("奇摩站");
        treeModel.insertNodeInto(leafnode, node3, node3.getChildCount());
        leafnode = new DefaultMutableTreeNode("职棒消息");
        treeModel.insertNodeInto(leafnode, node3, node3.getChildCount());
        leafnode = new DefaultMutableTreeNode("网络书店");
        treeModel.insertNodeInto(leafnode, node3, node3.getChildCount());
        
        JTree tree = new JTree(treeModel);
        tree.setRowHeight(20); 
        
        DefaultTreeCellRenderer cellRenderer = (DefaultTreeCellRenderer)tree.getCellRenderer();
        
        cellRenderer.setLeafIcon(new ImageIcon(".\\icons\\leaf.gif"));
        cellRenderer.setOpenIcon(new ImageIcon(".\\icons\\open.gif"));
        cellRenderer.setClosedIcon(new ImageIcon(".\\icons\\close.gif"));        cellRenderer.setFont(new Font("宋体",Font.PLAIN,12));
        cellRenderer.setBackgroundNonSelectionColor(Color.white);
        cellRenderer.setBackgroundSelectionColor(Color.yellow);
        cellRenderer.setBorderSelectionColor(Color.red);
        cellRenderer.setTextNonSelectionColor(Color.black);
        cellRenderer.setTextSelectionColor(Color.blue);
        
        tree.setEditable(true);
        JScrollPane scrollPane = new JScrollPane();
        scrollPane.setViewportView(tree);
        
        contentPane.add(scrollPane);
        f.pack();
        f.setVisible(true);
        
        f.addWindowListener(new WindowAdapter() {
            public void windowClosing(WindowEvent e) {
                System.exit(0);
            }
        });    }    public static void main(String args[]) {
    
        new TreeDemo4();
    }
}第61到63行设定图标的；