我不能在JTree节点和JPanel之间建立连接。 我有JTree节点：蓝色和紫色以及JPanel1和JPanel2。 节点蓝色必须与JPanel1连接，紫色与JPanel2连接。 但是当我点击节点时没有任何反应。 我不知道出了什么问题。有人可以帮忙吗？ 这是代码：
import javax.swing.JFrame;
import javax.swing.tree.TreePath;
/*
* To change this license header, choose License Headers in Project Properties.
* To change this template file, choose Tools | Templates
* and open the template in the editor.
*/
public class Tree extends javax.swing.JFrame {
static String lastComponent = "";
final JFrame jf = new JFrame("Test App");
/**
* Creates new form Tree
*/
public Tree() {
initComponents();
}
/**
* This method is called from within the constructor to initialize the form.
* WARNING: Do NOT modify this code. The content of this method is always
* regenerated by the Form Editor.
*/
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel3 = new javax.swing.JPanel();
jScrollPane2 = new javax.swing.JScrollPane();
jTree2 = new javax.swing.JTree();
jPanel1 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jPanel2 = new javax.swing.JPanel();
jButton1 = new javax.swing.JButton();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
javax.swing.tree.DefaultMutableTreeNode treeNode1 = new javax.swing.tree.DefaultMutableTreeNode("JTree");
javax.swing.tree.DefaultMutableTreeNode treeNode2 = new javax.swing.tree.DefaultMutableTreeNode("colors");
javax.swing.tree.DefaultMutableTreeNode treeNode3 = new javax.swing.tree.DefaultMutableTreeNode("blue");
treeNode2.add(treeNode3);
treeNode3 = new javax.swing.tree.DefaultMutableTreeNode("violet");
treeNode2.add(treeNode3);
treeNode1.add(treeNode2);
jTree2.setModel(new javax.swing.tree.DefaultTreeModel(treeNode1));
jTree2.addMouseListener(new java.awt.event.MouseAdapter() {
public void mouseClicked(java.awt.event.MouseEvent evt) {
jTree2MouseClicked(evt);
}
});
jScrollPane2.setViewportView(jTree2);
jPanel1.setLayout(new java.awt.CardLayout());
jLabel1.setText("jLabel1");
jPanel1.add(jLabel1, "card2");
jPanel2.setLayout(new java.awt.CardLayout());
jButton1.setText("jButton1");
jPanel2.add(jButton1, "card2");
javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
jPanel3.setLayout(jPanel3Layout);
jPanel3Layout.setHorizontalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 136, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 264, Short.MAX_VALUE))
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap()))
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap()))
);
jPanel3Layout.setVerticalGroup(
jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addComponent(jScrollPane2, javax.swing.GroupLayout.PREFERRED_SIZE, 275, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 25, Short.MAX_VALUE))
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap()))
.addGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel3Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.addContainerGap()))
);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
pack();
}// </editor-fold>
private void jTree2MouseClicked(java.awt.event.MouseEvent evt) {
TreePath path = jTree2.getPathForLocation(evt.getX(), evt.getY());
if (path != null) {
if (!lastComponent.equals("")) {
if (lastComponent.equals("blue")) {
jf.remove(jPanel1);
} else if (lastComponent.equals("violet")) {
jf.remove(jPanel2);
}
}
if (path.toString().contains("blue")) {
jf.add(jPanel1);
lastComponent = "blue";
} else if (path.toString().contains("violet")) {
jf.add(jPanel2);
lastComponent = "violet";
}
jf.repaint();
}
}
/**
* @param args the command line arguments
*/
public static void main(String args[]) {
/* Set the Nimbus look and feel */
//<editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) ">
/* If Nimbus (introduced in Java SE 6) is not available, stay with the default look and feel.
* For details see http://download.oracle.com/javase/tutorial/uiswing/lookandfeel/plaf.html
*/
try {
for (javax.swing.UIManager.LookAndFeelInfo info : javax.swing.UIManager.getInstalledLookAndFeels()) {
if ("Nimbus".equals(info.getName())) {
javax.swing.UIManager.setLookAndFeel(info.getClassName());
break;
}
}
} catch (ClassNotFoundException ex) {
java.util.logging.Logger.getLogger(Tree.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(Tree.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(Tree.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(Tree.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/* Create and display the form */
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new Tree().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JButton jButton1;
private javax.swing.JLabel jLabel1;
private javax.swing.JPanel jPanel1;
private javax.swing.JPanel jPanel2;
private javax.swing.JPanel jPanel3;
private javax.swing.JScrollPane jScrollPane2;
private javax.swing.JTree jTree2;
// End of variables declaration
}
答案 0 :(得分：2)
如果您想听取选择更改，首先应该附加TreeSelectionListener而不是MouseListener。请参阅Responding to Node Selection。
另一方面，在这些方面：
if (path.toString().contains("blue")) {
jf.add(jPanel1); // <-- here
lastComponent = "blue";
} else if (path.toString().contains("violet")) {
jf.add(jPanel2); // <-- here
lastComponent = "violet";
}
正如@peeskillet明智地指出你正在尝试将JPanel添加到JFrame（jf），这实际上是隐藏你的班级的班级成员（也是JFrame）。由于您似乎正在使用某些GUI构建器（我认为NetBeans），您可以：
最后，您可能需要考虑使用CardLayout并根据节点选择而不是add-revalidate-repaint进程切换卡片。