根据本教程，我在我的表单中添加了一个 JFileChooser ，但它在第一次加载表单时与表单一起出现。关于如何解决这个问题的任何想法？这是代码：
/*
* To change this template, choose Tools | Templates
* and open the template in the editor.
*/
package nysemarketpick;
import java.io.File;
import java.io.IOException;
import javax.swing.JFileChooser;
/**
*
* @author skiabox
*/
public class MainForm extends javax.swing.JFrame {
/**
* Creates new form MainForm
*/
public MainForm() {
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() {
mainPanel = new javax.swing.JPanel();
fileChooser = new javax.swing.JFileChooser();
jMenuBar1 = new javax.swing.JMenuBar();
jMenu1 = new javax.swing.JMenu();
Open = new javax.swing.JMenuItem();
Exit = new javax.swing.JMenuItem();
jMenu2 = new javax.swing.JMenu();
jMenu3 = new javax.swing.JMenu();
jMenu4 = new javax.swing.JMenu();
setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
setTitle("Nyse Stock Pick");
setSize(new java.awt.Dimension(1920, 1080));
org.jdesktop.layout.GroupLayout mainPanelLayout = new org.jdesktop.layout.GroupLayout(mainPanel);
mainPanel.setLayout(mainPanelLayout);
mainPanelLayout.setHorizontalGroup(
mainPanelLayout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 1082, Short.MAX_VALUE)
);
mainPanelLayout.setVerticalGroup(
mainPanelLayout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(0, 621, Short.MAX_VALUE)
);
jMenu1.setText("File");
Open.setText("Open");
Open.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
OpenActionPerformed(evt);
}
});
jMenu1.add(Open);
Exit.setText(" Exit");
Exit.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
ExitActionPerformed(evt);
}
});
jMenu1.add(Exit);
jMenuBar1.add(jMenu1);
jMenu2.setText("Options");
jMenuBar1.add(jMenu2);
jMenu3.setText("Tools");
jMenuBar1.add(jMenu3);
jMenu4.setText("Help");
jMenuBar1.add(jMenu4);
setJMenuBar(jMenuBar1);
org.jdesktop.layout.GroupLayout layout = new org.jdesktop.layout.GroupLayout(getContentPane());
getContentPane().setLayout(layout);
layout.setHorizontalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(mainPanel, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(0, 266, Short.MAX_VALUE)
.add(fileChooser, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.add(0, 266, Short.MAX_VALUE)))
);
layout.setVerticalGroup(
layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.addContainerGap()
.add(mainPanel, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.addContainerGap(43, Short.MAX_VALUE))
.add(layout.createParallelGroup(org.jdesktop.layout.GroupLayout.LEADING)
.add(layout.createSequentialGroup()
.add(0, 135, Short.MAX_VALUE)
.add(fileChooser, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE, org.jdesktop.layout.GroupLayout.DEFAULT_SIZE, org.jdesktop.layout.GroupLayout.PREFERRED_SIZE)
.add(0, 135, Short.MAX_VALUE)))
);
pack();
}// </editor-fold>
private void OpenActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
int returnVal = fileChooser.showOpenDialog(this);
if (returnVal == JFileChooser.APPROVE_OPTION)
{
File file = fileChooser.getSelectedFile();
//What to do with the file
PriceVolumeChart chart = new PriceVolumeChart(file.getName());
mainPanel = chart.myPanel;
}
else
{
System.out.println("File access cancelled by user.");
}
}
private void ExitActionPerformed(java.awt.event.ActionEvent evt) {
// TODO add your handling code here:
System.exit(0);
}
/**
* @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(MainForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (InstantiationException ex) {
java.util.logging.Logger.getLogger(MainForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (IllegalAccessException ex) {
java.util.logging.Logger.getLogger(MainForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
} catch (javax.swing.UnsupportedLookAndFeelException ex) {
java.util.logging.Logger.getLogger(MainForm.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
}
//</editor-fold>
/*
* Create and display the form
*/
java.awt.EventQueue.invokeLater(new Runnable() {
@Override
public void run() {
new MainForm().setVisible(true);
}
});
}
// Variables declaration - do not modify
private javax.swing.JMenuItem Exit;
private javax.swing.JMenuItem Open;
private javax.swing.JFileChooser fileChooser;
private javax.swing.JMenu jMenu1;
private javax.swing.JMenu jMenu2;
private javax.swing.JMenu jMenu3;
private javax.swing.JMenu jMenu4;
private javax.swing.JMenuBar jMenuBar1;
private javax.swing.JPanel mainPanel;
// End of variables declaration
}
大部分代码是从 netbeans 生成的。