Java JTree刷新而不折叠
刷新JTree实例时出现问题。请参阅以下代码:Java JTree刷新而不折叠,java,jtree,Java,Jtree,刷新JTree实例时出现问题。请参阅以下代码: import java.awt.EventQueue; import java.awt.event.ActionEvent; import java.awt.event.ActionListener; import javax.swing.GroupLayout; import javax.swing.GroupLayout.Alignment; import javax.swing.JButton; import javax.swing.JFr
import java.awt.EventQueue;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.GroupLayout;
import javax.swing.GroupLayout.Alignment;
import javax.swing.JButton;
import javax.swing.JFrame;
import javax.swing.JScrollPane;
import javax.swing.JTable;
import javax.swing.JTree;
import javax.swing.tree.DefaultMutableTreeNode;
import javax.swing.tree.DefaultTreeModel;
public class ItemTest {
private JFrame frame;
private DefaultMutableTreeNode root = new DefaultMutableTreeNode("Root");
private JTree tree = new JTree(root);
private JButton button = new JButton("Rebuild");
private String[] array = new String[] { "name", "first_name", "middle_name", "last_name"};
/**
* Launch the application.
*/
public static void main(String[] args) {
EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
try {
ItemTest window = new ItemTest();
window.frame.setVisible(true);
} catch (Exception e) {
e.printStackTrace();
}
}
});
}
/**
* Create the application.
*/
public ItemTest() {
initialize();
}
/**
* Initialize the contents of the frame.
*/
private void initialize() {
frame = new JFrame();
frame.setBounds(100, 100, 523, 349);
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
JScrollPane scrollBar = new JScrollPane();
GroupLayout groupLayout = new GroupLayout(frame.getContentPane());
groupLayout.setHorizontalGroup(
groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addContainerGap()
.addComponent(scrollBar, GroupLayout.PREFERRED_SIZE, 200, GroupLayout.PREFERRED_SIZE)
.addComponent(button, GroupLayout.PREFERRED_SIZE, 85, GroupLayout.PREFERRED_SIZE)
.addContainerGap(412, Short.MAX_VALUE))
);
groupLayout.setVerticalGroup(
groupLayout.createParallelGroup(Alignment.LEADING)
.addGroup(groupLayout.createSequentialGroup()
.addGap(22)
.addComponent(scrollBar, GroupLayout.DEFAULT_SIZE, 278, Short.MAX_VALUE)
.addComponent(button, GroupLayout.DEFAULT_SIZE, 25, Short.MAX_VALUE)
.addContainerGap())
);
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
root.add(new DefaultMutableTreeNode("Row 4"));
((DefaultTreeModel) tree.getModel()).nodeChanged(root);
}
});
for(String string : array) {
root.add(new DefaultMutableTreeNode(string));
}
scrollBar.setViewportView(tree);
frame.getContentPane().setLayout(groupLayout);
}
}
如果我们运行此代码,并展开“根”节点。我们将在其中看到4个节点。如果我们单击“重建”按钮,树将不会更新其自身。奇怪的是,如果我们不在开始时展开“根”节点(因此只需启动应用程序)并单击按钮,然后展开“根”节点,就会添加新行。是否有人知道如何在不崩溃的情况下刷新此树,因为在开始时展开“根”节点时,nodeChanged似乎不起作用
注意:我必须在不使用insertNodeInto的情况下完成此操作。您必须通知侦听器已插入节点:
button.addActionListener(new ActionListener() {
@Override
public void actionPerformed(ActionEvent arg0) {
root.add(new DefaultMutableTreeNode("Row 4"));
((DefaultTreeModel) tree.getModel()).nodesWereInserted(
root, new int[]{root.getChildCount()-1});
}
});
该死的,效果很好,你真的帮了我,非常感谢!