trees.java

一棵包含6个分支点的树的例子

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
class Branch{
  DefaultMutableTreeNode r;
  public Branch(String[] data){
    r=new DefaultMutableTreeNode(data[0]);
    for(int i=1;i<data.length;i++)
    r.add(new DefaultMutableTreeNode(data[i]));
  }
  public DefaultMutableTreeNode node(){
    return r;
  }
}
public class Trees extends JPanel{
  String [][]data={
    {"Colors","Red","Blue","Green"},
    {"Flavors","Tart","Sweet","Bland"},
    {"Length","Short","Medium","Long"},
    {"Volume","High","Medium","Low"},
    {"Temperature","High","Medium","Low"},
    {"Intensity","High","Medium","Low"},
  };
  static int i=0;
  DefaultMutableTreeNode root,child,chosen;
  JTree tree;
  DefaultTreeModel model;
  public Trees(){
    setLayout(new BorderLayout());
    root=new DefaultMutableTreeNode("root");
    tree=new JTree(root);
    add(new JScrollPane(tree));
    model=(DefaultTreeModel)tree.getModel();
    JButton test=new JButton("Press me");
    test.addActionListener(new ActionListener(){
      public void actionPerformed(ActionEvent e){
        if(i<data.length){
          child=new Branch(data[i++]).node();
          chosen=(DefaultMutableTreeNode)
             tree.getLastSelectedPathComponent();
             if(chosen==null)  chosen=root;
             model.insertNodeInto(child,chosen,0);
        }
      }
    });
    test.setBackground(Color.blue);
    test.setForeground(Color.white);
    JPanel p=new JPanel();
    p.add(test);
    add(p,BorderLayout.SOUTH);
  }
  public static void main(String args[]){
    JFrame jf=new JFrame("JTree demo");
    jf.getContentPane().add(new Trees(),BorderLayout.CENTER);
    jf.setSize(200,500);
    jf.setVisible(true);
  }
}