treedemo.java

来自「这是一个java程序」· Java 代码 · 共 50 行

import javax.swing.*; 
import javax.swing.tree.*;	
import java.awt.*;
import javax.swing.event.*;
class Tree extends JFrame implements TreeSelectionListener{   
    JTree tree;
    public Tree()  {
      Container con=getContentPane();//Returns the contentPane object for this frame
      DefaultMutableTreeNode root=new DefaultMutableTreeNode("中华人民共和国");
      DefaultMutableTreeNode node1=new DefaultMutableTreeNode("河北");//节点。
      DefaultMutableTreeNode node2=new DefaultMutableTreeNode("河南");
      DefaultMutableTreeNode node3=new DefaultMutableTreeNode("山东");
      DefaultMutableTreeNode nodeson1=new DefaultMutableTreeNode("邯郸");
      DefaultMutableTreeNode nodeson11=new DefaultMutableTreeNode("邯郸学院");
      DefaultMutableTreeNode nodeson12=new DefaultMutableTreeNode("河北工程大学");
      DefaultMutableTreeNode nodeson13=new DefaultMutableTreeNode("邯郸职业技术学院");
      DefaultMutableTreeNode nodeson2=new DefaultMutableTreeNode("石家庄");
      DefaultMutableTreeNode nodeson3=new DefaultMutableTreeNode("保定");
      root.add(node1);
      root.add(node2);
      root.add(node3);
      node1.add(nodeson1);
      node1.add(nodeson2);
      node1.add(nodeson3);
      nodeson1.add(nodeson11);
      nodeson1.add(nodeson12);
      nodeson1.add(nodeson13);
      tree=new JTree(root); 
    
      tree.addTreeSelectionListener(this);
      JScrollPane scrollpane=new JScrollPane(tree);
      con.add(scrollpane);
      setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      setVisible(true);
      setBounds(80,80,300,300);
      con.validate();//Validates this container and all of its subcomponents
      validate();
    }
    public void valueChanged(TreeSelectionEvent e) {
       DefaultMutableTreeNode node=(DefaultMutableTreeNode)tree.getLastSelectedPathComponent();
       if(node.isLeaf())
           this.setTitle((node.getUserObject()).toString());
    }
}
public class TreeDemo{
    public static void main(String args[]){
      Tree t=new Tree(); 
    } 
}