java - 隐藏面板时丢失JDialog标题(Java)

编辑：
当然，发布问题后2分钟我会找到答案。
How to completely remove an icon from JDialog?

但要跟进；有谁知道改变可调整大小属性时使图标状态保持一致的方法吗？

PS。我无法再回答自己的问题8个小时。

原始问题：
简而言之，这是一个有问题的简化示例代码。
当我单击“详细信息”（WinXP x32 Java 1.6）时，jPanel2更改可见性状态，并且由于某些原因与jPanel2一起更改了对话框图标。很好奇。
有人知道为什么图标与JPanel一起隐藏吗？
代码是由NetBeans 7.1生成的，仅稍作修改即可自包含。

在此先感谢您的帮助！

import java.awt.Frame;

import javax.swing.Icon;
import javax.swing.JOptionPane;
import javax.swing.UIManager;

public class TestHide extends javax.swing.JDialog {

  private static final long serialVersionUID = 1L;

  public TestHide(java.awt.Frame parent, boolean modal) {
    super(parent, modal);
    initComponents();
    jPanel2.setVisible(false);
    pack();
  }

  private void initComponents() {

    jPanel1 = new javax.swing.JPanel();
    lblIcon = new javax.swing.JLabel();
    jScrollPane1 = new javax.swing.JScrollPane();
    taShortMsg = new javax.swing.JTextArea();
    jPanel2 = new javax.swing.JPanel();
    jPanel3 = new javax.swing.JPanel();
    jLabel3 = new javax.swing.JLabel();
    jSeparator1 = new javax.swing.JSeparator();
    jSeparator2 = new javax.swing.JSeparator();
    jPanel4 = new javax.swing.JPanel();
    jSeparator3 = new javax.swing.JSeparator();
    jScrollPane2 = new javax.swing.JScrollPane();
    taDetails = new javax.swing.JTextArea();
    btnOk = new javax.swing.JButton();
    btnTgDetails = new javax.swing.JToggleButton();

    setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);

    lblIcon.setText(""); // NOI18N

    jScrollPane1.setBorder(null);

    taShortMsg.setBackground(getBackground());
    taShortMsg.setColumns(20);
    taShortMsg.setEditable(false);
    taShortMsg.setFont(lblIcon.getFont());
    taShortMsg.setLineWrap(true);
    taShortMsg.setRows(5);
    taShortMsg.setBorder(null);
    taShortMsg.setCursor(getCursor());
    taShortMsg.setOpaque(false);
    jScrollPane1.setViewportView(taShortMsg);

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
    jPanel1.setLayout(jPanel1Layout);
    jPanel1Layout.setHorizontalGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        jPanel1Layout.createSequentialGroup().addContainerGap().addComponent(lblIcon).addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
            .addComponent(jScrollPane1, javax.swing.GroupLayout.DEFAULT_SIZE, 399, Short.MAX_VALUE).addContainerGap()));
    jPanel1Layout.setVerticalGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        jPanel1Layout
            .createSequentialGroup()
            .addContainerGap()
            .addGroup(
                jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                    .addGroup(jPanel1Layout.createSequentialGroup().addComponent(lblIcon).addContainerGap(54, Short.MAX_VALUE))
                    .addComponent(jScrollPane1, javax.swing.GroupLayout.Alignment.TRAILING))));

    jPanel2.addComponentListener(new java.awt.event.ComponentAdapter() {
      public void componentHidden(java.awt.event.ComponentEvent evt) {
        jPanel2ComponentHidden(evt);
      }

      public void componentShown(java.awt.event.ComponentEvent evt) {
        jPanel2ComponentShown(evt);
      }
    });

    jLabel3.setText("jLabel3"); // NOI18N

    javax.swing.GroupLayout jPanel3Layout = new javax.swing.GroupLayout(jPanel3);
    jPanel3.setLayout(jPanel3Layout);
    jPanel3Layout.setHorizontalGroup(jPanel3Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        jPanel3Layout.createSequentialGroup().addContainerGap().addComponent(jSeparator1).addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED).addComponent(jLabel3)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED).addComponent(jSeparator2).addContainerGap()));
    jPanel3Layout
        .setVerticalGroup(jPanel3Layout
            .createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addGroup(
                javax.swing.GroupLayout.Alignment.TRAILING,
                jPanel3Layout
                    .createSequentialGroup()
                    .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
                    .addGroup(
                        jPanel3Layout
                            .createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                            .addComponent(jSeparator1, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 10,
                                javax.swing.GroupLayout.PREFERRED_SIZE)
                            .addComponent(jSeparator2, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.PREFERRED_SIZE, 10,
                                javax.swing.GroupLayout.PREFERRED_SIZE))).addComponent(jLabel3, javax.swing.GroupLayout.PREFERRED_SIZE, 22, javax.swing.GroupLayout.PREFERRED_SIZE));

    javax.swing.GroupLayout jPanel4Layout = new javax.swing.GroupLayout(jPanel4);
    jPanel4.setLayout(jPanel4Layout);
    jPanel4Layout.setHorizontalGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        jPanel4Layout.createSequentialGroup().addContainerGap().addComponent(jSeparator3).addContainerGap()));
    jPanel4Layout.setVerticalGroup(jPanel4Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(javax.swing.GroupLayout.Alignment.TRAILING,
        jPanel4Layout.createSequentialGroup().addContainerGap().addComponent(jSeparator3, javax.swing.GroupLayout.DEFAULT_SIZE, 0, Short.MAX_VALUE)));

    jScrollPane2.setBorder(null);

    taDetails.setColumns(20);
    taDetails.setEditable(false);
    taDetails.setFont(lblIcon.getFont());
    taDetails.setRows(5);
    jScrollPane2.setViewportView(taDetails);

    javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
    jPanel2.setLayout(jPanel2Layout);
    jPanel2Layout.setHorizontalGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jPanel3, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        .addGroup(jPanel2Layout.createSequentialGroup().addContainerGap().addComponent(jScrollPane2).addContainerGap())
        .addComponent(jPanel4, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE));
    jPanel2Layout.setVerticalGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        javax.swing.GroupLayout.Alignment.TRAILING,
        jPanel2Layout.createSequentialGroup()
            .addComponent(jPanel3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED).addComponent(jScrollPane2, javax.swing.GroupLayout.DEFAULT_SIZE, 129, Short.MAX_VALUE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jPanel4, javax.swing.GroupLayout.PREFERRED_SIZE, 8, javax.swing.GroupLayout.PREFERRED_SIZE)));

    btnOk.setText("OK"); // NOI18N
    btnOk.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(java.awt.event.ActionEvent evt) {
        btnOkActionPerformed(evt);
      }
    });

    btnTgDetails.setText("Details"); // NOI18N
    btnTgDetails.addActionListener(new java.awt.event.ActionListener() {
      public void actionPerformed(java.awt.event.ActionEvent evt) {
        btnTgDetailsActionPerformed(evt);
      }
    });

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
    getContentPane().setLayout(layout);
    layout.setHorizontalGroup(layout
        .createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
        .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
        .addGroup(
            layout.createSequentialGroup().addGap(0, 0, Short.MAX_VALUE).addComponent(btnOk, javax.swing.GroupLayout.PREFERRED_SIZE, 83, javax.swing.GroupLayout.PREFERRED_SIZE)
                .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
                .addComponent(btnTgDetails, javax.swing.GroupLayout.PREFERRED_SIZE, 83, javax.swing.GroupLayout.PREFERRED_SIZE).addContainerGap())
        .addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE));
    layout.setVerticalGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addGroup(
        layout
            .createSequentialGroup()
            .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addComponent(jPanel2, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
            .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
            .addGroup(
                layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING).addComponent(btnTgDetails)
                    .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup().addComponent(btnOk).addContainerGap()))));

    pack();
  }

  private void btnTgDetailsActionPerformed(java.awt.event.ActionEvent evt) {
    if (jPanel2.isVisible()) {
      btnTgDetails.setText("Details>>");
    } else {
      btnTgDetails.setText("Details<<");
    }
    jPanel2.setVisible(!jPanel2.isVisible());
    this.validate();
    this.pack();
  }

  private void btnOkActionPerformed(java.awt.event.ActionEvent evt) {
    dispose();
  }

  private void jPanel2ComponentHidden(java.awt.event.ComponentEvent evt) {
    setResizable(false);
  }

  private void jPanel2ComponentShown(java.awt.event.ComponentEvent evt) {
    setResizable(true);
  }

  public static void main(String args[]) {
    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(TestHide.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (InstantiationException ex) {
      java.util.logging.Logger.getLogger(TestHide.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (IllegalAccessException ex) {
      java.util.logging.Logger.getLogger(TestHide.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    } catch (javax.swing.UnsupportedLookAndFeelException ex) {
      java.util.logging.Logger.getLogger(TestHide.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
    }
    showMessageDialog(null, "I am title", "Small message...", "long\n\nlong\nmessage", JOptionPane.INFORMATION_MESSAGE);
  }

  public static void showMessageDialog(Frame parent, String title, String shortMessage, String longMessage, int type) {
    TestHide md = new TestHide(parent, true);
    Icon icon = null;
    switch (type) {
    case JOptionPane.ERROR_MESSAGE:
      icon = UIManager.getIcon("OptionPane.errorIcon");
      break;
    case JOptionPane.INFORMATION_MESSAGE:
      icon = UIManager.getIcon("OptionPane.informationIcon");
      break;
    case JOptionPane.WARNING_MESSAGE:
      icon = UIManager.getIcon("OptionPane.warningIcon");
      break;
    }

    md.setTitle(title);
    md.lblIcon.setIcon(icon);
    md.taShortMsg.setText(shortMessage);
    if (longMessage == null) {
      md.btnTgDetails.setVisible(false);
    } else {
      md.taDetails.setText(longMessage);
      md.taDetails.setCaretPosition(0);
    }
    md.pack();
    md.setVisible(true);
  }

  private javax.swing.JButton btnOk;
  private javax.swing.JToggleButton btnTgDetails;
  private javax.swing.JLabel jLabel3;
  private javax.swing.JPanel jPanel1;
  private javax.swing.JPanel jPanel2;
  private javax.swing.JPanel jPanel3;
  private javax.swing.JPanel jPanel4;
  private javax.swing.JScrollPane jScrollPane1;
  private javax.swing.JScrollPane jScrollPane2;
  private javax.swing.JSeparator jSeparator1;
  private javax.swing.JSeparator jSeparator2;
  private javax.swing.JSeparator jSeparator3;
  private javax.swing.JLabel lblIcon;
  private javax.swing.JTextArea taDetails;
  private javax.swing.JTextArea taShortMsg;
}

最佳答案

如果将以下语句放入类似的构造函数中

public TestHide(java.awt.Frame parent, boolean modal) {
super(parent, modal);
setIconImage(Toolkit.getDefaultToolkit().getImage("images\\white_title.png"));
initComponents();
jPanel2.setVisible(false);
pack();  }

标题栏上的图标就会不断出现。