Java树形菜单的创建

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(bZGjMp);

//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？

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