Java Swing:JTree DefaultMutableTreeNode未更新
我最近一直在从事一个Java Swing项目,今天我在修改Java Swing:JTree DefaultMutableTreeNode未更新,java,swing,jtree,children,treenode,Java,Swing,Jtree,Children,Treenode,我最近一直在从事一个Java Swing项目,今天我在修改DefaultMutableTreeNode的子节点时遇到了麻烦 以下SSCCE说明了该问题: import java.awt.event.*; import javax.swing.*; import javax.swing.tree.*; public class Test { private static boolean executed = false; public static void main(Strin
DefaultMutableTreeNode
的子节点时遇到了麻烦
以下SSCCE说明了该问题:
import java.awt.event.*;
import javax.swing.*;
import javax.swing.tree.*;
public class Test
{
private static boolean executed = false;
public static void main(String[] args)
{
SwingUtilities.invokeLater(new Runnable()
{
@Override
public void run()
{
JFrame frame = new JFrame();
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
//
final DefaultMutableTreeNode root = new DefaultMutableTreeNode("root");
final JTree tree = new JTree(root);
tree.addMouseListener(new MouseAdapter()
{
@Override
public void mousePressed(MouseEvent ev)
{
if (ev.getClickCount() == 2)
{
root.removeAllChildren();
for (String s: get())
{
root.add(new DefaultMutableTreeNode(s));
System.out.println(s + " added");
}
System.out.println();
tree.expandPath(tree.getSelectionPath());
}
}
});
frame.add(tree);
frame.setSize(200,200);
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
});
}
static String[] get()
{
if (!executed)
{
executed = true;
return new String[]{"a","b","c"};
}
else return new String[]{"a","b","c","d"};
}
}
如您所见,第一次调用get()
方法时,它返回一个3元素数组,然后返回一个4元素数组。当我第一次双击(实际按下)根节点时,应该有三个子节点(a、b和c),程序的行为符合预期。当我再次双击根节点时,我想它将有四个子节点。但事实并非如此。第二次双击时,仍然只有三个子节点,而不是四个子节点
我犯了错误吗?提前感谢您的帮助。您应该使用
reload()
方法通知模型更改
在展开路径
之前添加此行,如下所示
DefaultTreeModel model = (DefaultTreeModel) tree.getModel();
model.reload(root); // notify changes to model
tree.expandPath(tree.getSelectionPath());
使用
SwingUtilities.invokeLater(Runnable)
更新树怎么样?