树的创建及点击事件Java

最新推荐文章于 2024-03-30 20:13:01 发布

原创最新推荐文章于 2024-03-30 20:13:01 发布 · 770 阅读

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CC 4.0 BY-SA版权

本文介绍了一个使用 Java Swing 的 JTree 控件创建树形结构视图的示例，演示了如何构建树节点、设置选择模式及监听选择变化。

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import java.awt.BorderLayout;
import java.nio.file.Paths;

import javax.swing.JFrame;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
import javax.swing.tree.TreePath;
import javax.swing.tree.TreeSelectionModel;

public class Tree extends JFrame{
public Tree(){//构造方法
	DefaultMutableTreeNode root=new DefaultMutableTreeNode("根节点");
	DefaultMutableTreeNode nodeFirst=new DefaultMutableTreeNode("一级子节点A");
	root.add(nodeFirst);//将一级节点添加到根节点
	//创建不允许有子节点的二级节点
	DefaultMutableTreeNode nodeSecond=new DefaultMutableTreeNode("二级子节点",false);
	nodeFirst.add(nodeSecond);
	root.add(new DefaultMutableTreeNode("一级子节点B"));
	JTree treeRoot=new JTree(root);//利用根节点直接创建树
	getContentPane().add(treeRoot,BorderLayout.WEST);
	//利用根节点创建树模型，采用默认的判断方式
	DefaultTreeModel treeModelDefault=new DefaultTreeModel(root);
	JTree treeDefault=new JTree(treeModelDefault);
	getContentPane().add(treeDefault, BorderLayout.CENTER);
	//利用根节点创建树模型并采用非默认的判断方式
	DefaultTreeModel treeModelPointed=new DefaultTreeModel(root,true);
	JTree treePointed=new JTree(treeModelPointed);
	getContentPane().add(treePointed, BorderLayout.EAST);
	TreeSelectionModel treeSelectionModel=treeRoot.getSelectionModel();//获得树的选择模型
	treeSelectionModel.setSelectionMode(TreeSelectionModel.CONTIGUOUS_TREE_SELECTION);//设置为连选
	treeRoot.addTreeSelectionListener(new TreeSelectionListener(){
		public void valueChanged(TreeSelectionEvent e){
			if(!treeRoot.isSelectionEmpty()){
				TreePath[] selectionPaths=treeRoot.getSelectionPaths();//获得所有被选中节点路径的数组
				for(int i=0;i<selectionPaths.length;i++){
					TreePath treePath=selectionPaths[i];
					//以数组的形式返回路径中所有节点的对象
					Object[] path=treePath.getPath();
					for(int j=0;j<path.length;j++){
						DefaultMutableTreeNode node=(DefaultMutableTreeNode)path[j];
						System.out.print(node.getUserObject()+(j==(path.length-1)?"":"-->"));
					}
					System.out.println();
				}
				System.out.println();
				
			}
		}
	});
	
	setSize(350,100);
	setVisible(true);
	setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
}
	public static void main(String[] args) {
		 new Tree();
	}
	 
}