JTree的使用

引用：https://blog.youkuaiyun.com/u013506294/article/details/51320193

 

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



public class TreeDemo {
	public static void main(String[] args) {

		// 创建没有父节点和子节点、但允许有子节点的树节点，并使用指定的用户对象对它进行初始化。
		// public DefaultMutableTreeNode(Object userObject)
		DefaultMutableTreeNode node1 = new DefaultMutableTreeNode("AAA");
		node1.add(new DefaultMutableTreeNode(new User("A1")));
		node1.add(new DefaultMutableTreeNode(new User("A2")));
		node1.add(new DefaultMutableTreeNode(new User("A3")));



		DefaultMutableTreeNode node2 = new DefaultMutableTreeNode("BBB");
		node2.add(new DefaultMutableTreeNode(new User("B1")));
		node2.add(new DefaultMutableTreeNode(new User("B2")));
		node2.add(new DefaultMutableTreeNode(new User("B3")));



		DefaultMutableTreeNode top = new DefaultMutableTreeNode("C");



		top.add(new DefaultMutableTreeNode(new User("C1")));

		top.add(node1);
		top.add(node2);

		final JTree tree = new JTree(top);
		JFrame f = new JFrame("JTreeDemo");
		f.add(tree);
		f.setSize(300, 300);
		f.setVisible(true);
		f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

		// 添加选择事件

		tree.addTreeSelectionListener(new TreeSelectionListener() {
			public void valueChanged(TreeSelectionEvent e) {
				DefaultMutableTreeNode node = (DefaultMutableTreeNode) tree.getLastSelectedPathComponent();

				if (node == null) {
					return;
				}
				Object object = node.getUserObject();
				if (node.isLeaf()) {
					User user = (User) object;
					System.out.println("你选择了：" + user.toString());

				}

		}
		});
	}
}



class User {

	private String name;
	public User(String n) {
		name = n;

	}



	// 重点在toString，节点的显示文本就是toString

	public String toString() {
		return name;

	}

}