Java树形菜单的创建

功能：实现创建一个树形菜单
说明：创建树形菜单结构与创建菜单栏类似，是按层次与模型创建的。
通过defaultmutabletreenode类创建根节点、子节点和孙节点对象，再通过defaulttreemodel
类利用根节点创建树模型对象，然后通过treemodel.insertnodeinto方法将节点对象插入树模型中。

效果图：

代码：

import java.awt.*; 
import javax.swing.*; 
import javax.swing.tree.*; 
import javax.swing.event.*; 
public class tree extends jframe implements treeselectionlistener 
{ 
 private jlabel label; 
 
 public tree() 
 { 
  super("树形菜单"); setsize(400,400); 
  container container = getcontentpane(); 
 
  //创建根节点和子节点 
  defaultmutabletreenode root = new defaultmutabletreenode("文本编辑器"); 
  defaultmutabletreenode node1 = new defaultmutabletreenode("文件"); 
  defaultmutabletreenode node2 = new defaultmutabletreenode("编辑"); 
  //利用根节点创建treemodel 
  defaulttreemodel treemodel = new defaulttreemodel(root); 
  //插入子节点node1,node2 
  treemodel.insertnodeinto(node1,root,root.getchildcount()); 
  treemodel.insertnodeinto(node2,root,root.getchildcount()); 
 
  //创建节点node1的子节点并插入 
  defaultmutabletreenode leafnode = new defaultmutabletreenode("打开"); 
  treemodel.insertnodeinto(leafnode,node1,node1.getchildcount()); 
  leafnode = new defaultmutabletreenode("保存"); 
  treemodel.insertnodeinto(leafnode,node1,node1.getchildcount()); 
  leafnode = new defaultmutabletreenode("另存为"); 
  treemodel.insertnodeinto(leafnode,node1,node1.getchildcount()); 
  leafnode = new defaultmutabletreenode("关闭"); 
  treemodel.insertnodeinto(leafnode,node1,node1.getchildcount()); 
 
  //创建节点node2的子节点并插入 
  leafnode = new defaultmutabletreenode("剪切"); 
  treemodel.insertnodeinto(leafnode,node2,node2.getchildcount()); 
  leafnode = new defaultmutabletreenode("复制"); 
  treemodel.insertnodeinto(leafnode,node2,node2.getchildcount()); 
  leafnode = new defaultmutabletreenode("粘贴"); 
  treemodel.insertnodeinto(leafnode,node2,node2.getchildcount()); 
 
  //创建树对象 
  jtree tree = new jtree(treemodel); 
  //设置tree的选择为一次只能选择一个节点 
  tree.getselectionmodel().setselectionmode( 
       treeselectionmodel.single_tree_selection); 
  //注册监听器 
  tree.addtreeselectionlistener(this); 
 
  tree.setrowheight(20); 
 
  //创建节点绘制对象 
  defaulttreecellrenderer cellrenderer = 
       (defaulttreecellrenderer)tree.getcellrenderer(); 
 
  //设置字体 
  cellrenderer.setfont(new font("serif",font.plain,14)); 
  cellrenderer.setbackgroundnonselectioncolor(color.white); 
  cellrenderer.setbackgroundselectioncolor(color.yellow); 
  cellrenderer.setborderselectioncolor(color.red); 
 
  //设置选或不选时，文字的变化颜色 
  cellrenderer.settextnonselectioncolor(color.black); 
  cellrenderer.settextselectioncolor(color.blue); 
   
  //把树对象添加到内容面板 
  container.add(new jscrollpane(tree)); 
 
  //创建标签 
  label = new jlabel("你当前选择的节点为：",jlabel.center); 
  label.setfont(new font("serif",font.plain,14)); 
  container.add(label,borderlayout.south); 
 
  setvisible(true); //设置可见 
  setdefaultcloseoperation(jframe.exit_on_close); //设置窗口关闭动作 
 } 
 
 //处理treeselectionevent事件 
 public void valuechanged(treeselectionevent event) 
 { 
  jtree tree = (jtree)event.getsource(); 
  //获取目前选取的节点 
  defaultmutabletreenode selectionnode = 
   (defaultmutabletreenode)tree.getlastselectedpathcomponent(); 
  string nodename = selectionnode.tostring(); 
  label.settext("你当前选取的节点为： "+nodename); 
 } 
 
 public static void main(string args[]) 
 { 
  tree d = new tree(); 
 } 
 
} 

本文按层次与模型创建的树形菜单，与创建菜单栏类似，不知道小伙伴们有没有掌握呐？