声明已创建的JDialog

Question

这个问题可能没有任何意义，因为我非常困惑。我正在Netbeans中使用Swing创建一个UI。我使用Swing UI创建了一个对话框。我想在单击主框架上的按钮时打开此对话框。在源代码中，它已经将我的对话框声明为一个变量。当我尝试在这个对话框变量上使用setVisible时，它显示的是对话框的顶部、标题和退出按钮，而不是我添加到对话框中的任何按钮或文本。有人告诉我必须声明这个对话框，但它还没有被自动生成的代码声明吗？

public class ComputeUI extends javax.swing.JFrame {
/**
* Creates new form ComputeUI
*/
public ComputeUI() {
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() {
GCDDialog = new javax.swing.JDialog();
jPanel1 = new javax.swing.JPanel();
jLabel5 = new javax.swing.JLabel();
jButton3 = new javax.swing.JButton();
jTextField2 = new javax.swing.JTextField();
jLabel9 = new javax.swing.JLabel();
jLabel10 = new javax.swing.JLabel();

jLabel2 = new javax.swing.JLabel();
jLabel7 = new javax.swing.JLabel();
jButton2 = new javax.swing.JButton();
jTextField1 = new javax.swing.JTextField();
jLabel8 = new javax.swing.JLabel();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
jMenuItem2 = new javax.swing.JMenuItem();
jMenu2 = new javax.swing.JMenu();
jMenuItem1 = new javax.swing.JMenuItem();

GCDDialog.setDefaultCloseOperation(javax.swing.WindowConstants.DISPOSE_ON_CLOSE);
GCDDialog.setTitle("GCD");
GCDDialog.setAlwaysOnTop(true);
GCDDialog.setLocationByPlatform(true);
GCDDialog.setModalityType(java.awt.Dialog.ModalityType.APPLICATION_MODAL);
GCDDialog.setName("GCDDialog"); // NOI18N
jLabel5.setText("Number:");
jButton3.setText("Compute");

javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
jPanel1.setLayout(jPanel1Layout);
jPanel1Layout.setHorizontalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(20, 20, 20)
.addComponent(jLabel5)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, 81, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jButton3))
.addGroup(jPanel1Layout.createSequentialGroup()
.addContainerGap()
.addComponent(jLabel9)
.addGap(18, 18, 18)
.addComponent(jLabel10)))
.addContainerGap(171, Short.MAX_VALUE))
);
jPanel1Layout.setVerticalGroup(
jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel1Layout.createSequentialGroup()
.addGap(22, 22, 22)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel5)
.addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGap(25, 25, 25)
.addComponent(jButton3)
.addGap(33, 33, 33)
.addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jLabel9)
.addComponent(jLabel10))
.addContainerGap(71, Short.MAX_VALUE))
);
javax.swing.GroupLayout GCDDialogLayout = new javax.swing.GroupLayout(GCDDialog.getContentPane());
GCDDialog.getContentPane().setLayout(GCDDialogLayout);
GCDDialogLayout.setHorizontalGroup(
GCDDialogLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
);
GCDDialogLayout.setVerticalGroup(
GCDDialogLayout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(GCDDialogLayout.createSequentialGroup()
.addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(0, 0, Short.MAX_VALUE))
);
GCDDialog.getAccessibleContext().setAccessibleName("GCDDialog");

setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
jMenu1.setText("File");
jMenuItem2.setText("Exit");
jMenuItem2.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jMenuItem2ActionPerformed(evt);
}
});
jMenu1.add(jMenuItem2);
jMenuBar1.add(jMenu1);
jMenu2.setText("Compute");
jMenuItem1.setText("GCD");
jMenuItem1.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jMenuItem1ActionPerformed(evt);
}
});
jMenu2.add(jMenuItem1);


jMenuBar1.add(jMenu2);
setJMenuBar(jMenuBar1);
javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 400, Short.MAX_VALUE)
);
layout.setVerticalGroup(
layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGap(0, 279, Short.MAX_VALUE)
);
pack();
}// </editor-fold>                        
private void jMenuItem2ActionPerformed(java.awt.event.ActionEvent evt) {                                           
// TODO add your handling code here:
System.exit(0);
}                                          
private void jMenuItem1ActionPerformed(java.awt.event.ActionEvent evt) {                                           
// TODO add your handling code here:
GCDDialog.setVisible(true);
}                                          
/**
* @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(ComputeUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(ComputeUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(ComputeUI.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(ComputeUI.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 ComputeUI().setVisible(true);
}
});
}
// Variables declaration - do not modify                     

private javax.swing.JDialog GCDDialog;
private javax.swing.JButton jButton2;
private javax.swing.JButton jButton3;
private javax.swing.JLabel jLabel10;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel5;
private javax.swing.JLabel jLabel7;
private javax.swing.JLabel jLabel8;
private javax.swing.JLabel jLabel9;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JMenuItem jMenuItem1;
private javax.swing.JMenuItem jMenuItem2;

private javax.swing.JPanel jPanel1;
private javax.swing.JTextField jTextField1;
private javax.swing.JTextField jTextField2;
// End of variables declaration                   
} 

Answer 1

您需要在setVisible(true)之前对创建的JDialog GCDDialog调用pack()。(旁注：变量名不应以大写字母开头(

一次只能为一个表单使用Netbeans表单设计器。所以你应该有ComputeUI.java和GCDDialog.java。这样Netbeans将正确初始化这两个表单。

要在两个组件之间建立链接，请在ComputeUI类中：

• 声明一个全局变量：GCDDialog myDialog;
• 在构造函数中：myDialog = new GCDDialog(...);//如果通过Netbeans表单设计器创建，则会自动调用pack((
• 和在jMenuItem1ActionPerformed:myDialog.setVisible(true);中