擴展特定的JTree路徑

Question

我在擴展JTree節點時遇到問題。 我開始使用時選擇一個節點，但是所選節點的路徑和所選節點本身都要折疊。 我試過用了

tree.collapsePath(new TreePath(tree.getModel().getRoot()));
tree.expandPath(new TreePath(e111.getPath()));

像這樣的東西，但它似乎沒有任何影響，我真的不知道我怎么能這樣做

這是我的樹的樣子：

http://img220.imageshack.us/img220/3450/jtreepng.png

如果我單擊1.1.1我希望其他所有內容都被折疊，但1.1.1節點和路徑中的元素將被折疊。

這是我創建的應用程序：

public class SelectableTree extends JFrame implements TreeSelectionListener {
public static void main(String[] args) {
    new SelectableTree();
}

DefaultMutableTreeNode root;
DefaultMutableTreeNode e1;
DefaultMutableTreeNode e2;
DefaultMutableTreeNode e3;

DefaultMutableTreeNode e11;
DefaultMutableTreeNode e22;
DefaultMutableTreeNode e33;

DefaultMutableTreeNode e111;
DefaultMutableTreeNode e222;
DefaultMutableTreeNode e333;

DefaultMutableTreeNode aChild;
private JTree tree;
private JTextField currentSelectionField;

public SelectableTree() {
    super("JTree Selections");
    WindowUtilities.setNativeLookAndFeel();
    addWindowListener(new ExitListener());
    Container content = getContentPane();
    root = new DefaultMutableTreeNode("Root");

    e1 = new DefaultMutableTreeNode("1");
    e2 = new DefaultMutableTreeNode("2");
    e3 = new DefaultMutableTreeNode("3");

    e11 = new DefaultMutableTreeNode("1.1");
    e22 = new DefaultMutableTreeNode("2.2");
    e33 = new DefaultMutableTreeNode("3.3");

    e111 = new DefaultMutableTreeNode("1.1.1");
    e222 = new DefaultMutableTreeNode("2.2.2");
    e333 = new DefaultMutableTreeNode("3.3.3");

    root.add(e1);
    root.add(e2);
    root.add(e3);
    e1.add(e11);
    e2.add(e22);
    e3.add(e33);
    e11.add(e111);
    e22.add(e222);
    e33.add(e333);

    tree = new JTree(root);
    tree.addTreeSelectionListener(this);
    content.add(new JScrollPane(tree), BorderLayout.CENTER);
    currentSelectionField = new JTextField("Current Selection: NONE");
    content.add(currentSelectionField, BorderLayout.SOUTH);
    setSize(250, 275);
    setVisible(true);
}

public void valueChanged(TreeSelectionEvent event) {
    tree.clearSelection();
    tree.collapsePath(new TreePath(tree.getModel().getRoot()));
    tree.expandPath(new TreePath(e111.getPath()));
}

編輯：奇怪的是， tree.collapsePath工作得很好，似乎是tree.expandPath(new TreePath(e111.getPath())); 是問題

Answer 1

應該僅在事件派發線程上構造和操作Swing GUI對象。

import java.awt.BorderLayout;
import java.awt.EventQueue;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTextField;
import javax.swing.JTree;
import javax.swing.event.TreeSelectionEvent;
import javax.swing.event.TreeSelectionListener;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.TreePath;

public class SelectableTree extends JFrame implements TreeSelectionListener {

    public static void main(String[] args) {
        EventQueue.invokeLater(new Runnable() {

            @Override
            public void run() {
                new SelectableTree();
            }
        });
    }
    DefaultMutableTreeNode root;
    DefaultMutableTreeNode e1 = new DefaultMutableTreeNode("1");
    DefaultMutableTreeNode e2 = new DefaultMutableTreeNode("2");
    DefaultMutableTreeNode e3 = new DefaultMutableTreeNode("3");
    DefaultMutableTreeNode e11 = new DefaultMutableTreeNode("1.1");
    DefaultMutableTreeNode e22 = new DefaultMutableTreeNode("2.2");
    DefaultMutableTreeNode e33 = new DefaultMutableTreeNode("3.3");
    DefaultMutableTreeNode e111 = new DefaultMutableTreeNode("1.1.1");
    DefaultMutableTreeNode e222 = new DefaultMutableTreeNode("2.2.2");
    DefaultMutableTreeNode e333 = new DefaultMutableTreeNode("3.3.3");
    DefaultMutableTreeNode aChild;
    private JTree tree;
    private JTextField currentSelectionField;

    public SelectableTree() {
        super("JTree Selections");
        setDefaultCloseOperation(EXIT_ON_CLOSE);
        root = new DefaultMutableTreeNode("Root");
        root.add(e1);
        root.add(e2);
        root.add(e3);
        e1.add(e11);
        e2.add(e22);
        e3.add(e33);
        e11.add(e111);
        e22.add(e222);
        e33.add(e333);

        tree = new JTree(root);
        tree.addTreeSelectionListener(this);
        add(new JScrollPane(tree), BorderLayout.CENTER);
        currentSelectionField = new JTextField("Current Selection: NONE");
        add(currentSelectionField, BorderLayout.SOUTH);
        setSize(250, 275);
        setLocationRelativeTo(null);
        setVisible(true);
    }

    @Override
    public void valueChanged(TreeSelectionEvent event) {
        tree.expandPath(new TreePath(e11.getPath()));
        currentSelectionField.setText(event.getPath().toString());
    }
}

Answer 2

您是否檢查了expandPath方法的javadoc。 該方法完全符合它的描述：

如果路徑中的最后一項是葉子，則無效。

Answer 3

使用

tree.setSelectionPath(new TreePath(e111.getPath()));

代替

tree.expandPath(new TreePath(e111.getPath()));