每次运行时，都会显示Build Successful。但是没有显示输出。我尝试过配置项目的主要课程，但没有工作。这段代码有什么要重新检查的吗？我已经粘贴了整个代码。
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.sql.Connection;
import java.sql.DriverManager;
import java.sql.PreparedStatement;
import java.sql.ResultSet;
import java.sql.SQLException;
import java.sql.Statement;
import java.util.logging.Level;
import java.util.logging.Logger;
import javax.swing.JOptionPane;
import javax.swing.Timer;
import static sun.management.snmp.jvminstr.JvmThreadInstanceEntryImpl.ThreadStateMap.Byte0.runnable;
public class loginPanel extends javax.swing.JPanel {
public loginPanel() {
initComponents();
}
@SuppressWarnings("unchecked")
// <editor-fold defaultstate="collapsed" desc="Generated Code">
private void initComponents() {
jPanel2 = new javax.swing.JPanel();
jLabel1 = new javax.swing.JLabel();
jLabel2 = new javax.swing.JLabel();
jEmailField = new javax.swing.JTextField();
jLabel3 = new javax.swing.JLabel();
jSeparator1 = new javax.swing.JSeparator();
jPasswordField = new javax.swing.JPasswordField();
jSeparator2 = new javax.swing.JSeparator();
showPassword = new javax.swing.JCheckBox();
jSignIn = new javax.swing.JButton();
jRegister = new javax.swing.JButton();
jButton3 = new javax.swing.JButton();
jSeparator3 = new javax.swing.JSeparator();
jPanel1 = new javax.swing.JPanel();
jPanel1Label3 = new javax.swing.JLabel();
jPanel1Label2 = new javax.swing.JLabel();
jPanel1Label1 = new javax.swing.JLabel();
jLabel4 = new javax.swing.JLabel();
jLabel8 = new javax.swing.JLabel();
setLayout(new org.netbeans.lib.awtextra.AbsoluteLayout());
jPanel2.setBackground(new java.awt.Color(36, 47, 65));
jLabel1.setFont(new java.awt.Font("Yu Gothic", 1, 48)); // NOI18N
jLabel1.setForeground(new java.awt.Color(0, 204, 153));
jLabel1.setText("Login");
jLabel2.setFont(new java.awt.Font("Ubuntu", 1, 24)); // NOI18N
jLabel2.setForeground(new java.awt.Color(255, 255, 255));
jLabel2.setText("Email");
jEmailField.setBackground(new java.awt.Color(36, 47, 65));
jEmailField.setFont(new java.awt.Font("Verdana", 0, 14)); // NOI18N
jEmailField.setForeground(new java.awt.Color(204, 204, 204));
jEmailField.setText("Enter Your Email");
jEmailField.setToolTipText("");
jEmailField.setBorder(null);
jLabel3.setBackground(new java.awt.Color(36, 47, 65));
jLabel3.setFont(new java.awt.Font("Ubuntu", 1, 24)); // NOI18N
jLabel3.setForeground(new java.awt.Color(255, 255, 255));
jLabel3.setText("Password");
jPasswordField.setEditable(false);
jPasswordField.setBackground(new java.awt.Color(36, 47, 65));
jPasswordField.setFont(new java.awt.Font("Verdana", 0, 14)); // NOI18N
jPasswordField.setForeground(new java.awt.Color(204, 204, 204));
jPasswordField.setText("dsfsdfdsfsdfsdfsf");
jPasswordField.setBorder(null);
showPassword.setBackground(new java.awt.Color(36, 47, 65));
showPassword.setFont(new java.awt.Font("Ubuntu", 0, 12)); // NOI18N
showPassword.setForeground(new java.awt.Color(255, 255, 255));
showPassword.setText("Show Password");
showPassword.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
showPasswordActionPerformed(evt);
}
});
jSignIn.setBackground(new java.awt.Color(255, 102, 102));
jSignIn.setFont(new java.awt.Font("Ubuntu", 1, 24)); // NOI18N
jSignIn.setForeground(new java.awt.Color(255, 255, 255));
jSignIn.setText("Sign In");
jSignIn.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jSignInActionPerformed(evt);
}
});
jRegister.setBackground(new java.awt.Color(255, 102, 102));
jRegister.setFont(new java.awt.Font("Ubuntu", 1, 24)); // NOI18N
jRegister.setForeground(new java.awt.Color(255, 255, 255));
jRegister.setText("Register");
jRegister.addActionListener(new java.awt.event.ActionListener() {
public void actionPerformed(java.awt.event.ActionEvent evt) {
jRegisterActionPerformed(evt);
}
});
jButton3.setBackground(new java.awt.Color(0, 204, 204));
jButton3.setText("Forgot Password");
javax.swing.GroupLayout jPanel2Layout = new javax.swing.GroupLayout(jPanel2);
jPanel2.setLayout(jPanel2Layout);
jPanel2Layout.setHorizontalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(172, 172, 172)
.addComponent(jLabel1))
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(79, 79, 79)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false)
.addComponent(jLabel3)
.addComponent(jLabel2)
.addComponent(jEmailField)
.addComponent(jSeparator1)
.addComponent(jPasswordField)
.addComponent(jSeparator2, javax.swing.GroupLayout.PREFERRED_SIZE, 328, javax.swing.GroupLayout.PREFERRED_SIZE))
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(16, 16, 16)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addComponent(jSeparator3, javax.swing.GroupLayout.PREFERRED_SIZE, 326, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGroup(jPanel2Layout.createSequentialGroup()
.addComponent(jSignIn, javax.swing.GroupLayout.PREFERRED_SIZE, 132, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(63, 63, 63)
.addComponent(jRegister))))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addGap(114, 114, 114)
.addComponent(showPassword)
.addGap(117, 117, 117)))))
.addContainerGap(79, Short.MAX_VALUE))
.addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel2Layout.createSequentialGroup()
.addGap(0, 0, Short.MAX_VALUE)
.addComponent(jButton3)
.addGap(183, 183, 183))
);
jPanel2Layout.setVerticalGroup(
jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
.addGroup(jPanel2Layout.createSequentialGroup()
.addGap(94, 94, 94)
.addComponent(jLabel1)
.addGap(55, 55, 55)
.addComponent(jLabel2)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jEmailField, javax.swing.GroupLayout.PREFERRED_SIZE, 23, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jSeparator1, javax.swing.GroupLayout.PREFERRED_SIZE, 10, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jLabel3)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(jPasswordField, javax.swing.GroupLayout.PREFERRED_SIZE, 29, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED)
.addComponent(jSeparator2, javax.swing.GroupLayout.PREFERRED_SIZE, 10, javax.swing.GroupLayout.PREFERRED_SIZE)
.addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
.addComponent(showPassword)
.addGap(63, 63, 63)
.addGroup(jPanel2Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE)
.addComponent(jRegister)
.addComponent(jSignIn))
.addGap(18, 18, 18)
.addComponent(jSeparator3, javax.swing.GroupLayout.PREFERRED_SIZE, 10, javax.swing.GroupLayout.PREFERRED_SIZE)
.addGap(18, 18, 18)
.addComponent(jButton3)
.addContainerGap(64, Short.MAX_VALUE))
);
add(jPanel2, new org.netbeans.lib.awtextra.AbsoluteConstraints(530, 0, 500, 670));
jPanel1.setBackground(new java.awt.Color(255, 153, 153));
jPanel1.setLayout(null);
jPanel1Label3.setFont(new java.awt.Font("Times New Roman", 1, 24)); // NOI18N
jPanel1Label3.setForeground(new java.awt.Color(255, 204, 51));
jPanel1Label3.setText("Chase Your Dream");
jPanel1Label3.setToolTipText("");
jPanel1.add(jPanel1Label3);
jPanel1Label3.setBounds(160, 530, 200, 60);
jPanel1Label2.setBackground(new java.awt.Color(255, 255, 255));
jPanel1Label2.setIcon(new javax.swing.ImageIcon("C:\\Users\\Roy\\Documents\\NetBeansProjects\\login_form_1\\roy-hill.png")); // NOI18N
jPanel1.add(jPanel1Label2);
jPanel1Label2.setBounds(90, 200, 300, 260);
jPanel1Label1.setFont(new java.awt.Font("Monotype Corsiva", 1, 48)); // NOI18N
jPanel1Label1.setForeground(new java.awt.Color(255, 153, 153));
jPanel1Label1.setText("Login Panel 1");
jPanel1.add(jPanel1Label1);
jPanel1Label1.setBounds(120, 120, 300, 50);
jLabel4.setIcon(new javax.swing.ImageIcon("C:\\Users\\Roy\\Documents\\NetBeansProjects\\login_form_1\\Spiral.png")); // NOI18N
jLabel4.setText("jLabel4");
jPanel1.add(jLabel4);
jLabel4.setBounds(260, 0, 310, 670);
jLabel8.setIcon(new javax.swing.ImageIcon("C:\\Users\\Roy\\Documents\\NetBeansProjects\\login_form_1\\Mac01.jpg")); // NOI18N
jPanel1.add(jLabel8);
jLabel8.setBounds(0, 0, 530, 670);
add(jPanel1, new org.netbeans.lib.awtextra.AbsoluteConstraints(0, 0, 530, 670));
}// </editor-fold>
//Show or Hide Password Operation:
private void showPasswordActionPerformed(java.awt.event.ActionEvent evt) {
if(showPassword.isSelected()){
jPasswordField.setEchoChar((char)0);
}else{
jPasswordField.setEchoChar('*');
}
}
private void jRegisterActionPerformed(java.awt.event.ActionEvent evt) {
}
private void jSignInActionPerformed(java.awt.event.ActionEvent evt) {
}
public static void main(String [] args){
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
new loginPanel().setVisible(true);
}
});
}
private void jSignInActionPerformed(java.awt.event.ActionEvent evt) {
}
}
private javax.swing.JButton jButton3;
private javax.swing.JTextField jEmailField;
private javax.swing.JLabel jLabel1;
private javax.swing.JLabel jLabel2;
private javax.swing.JLabel jLabel3;
private javax.swing.JLabel jLabel4;
private javax.swing.JLabel jLabel8;
private javax.swing.JPanel jPanel1;
private javax.swing.JLabel jPanel1Label1;
private javax.swing.JLabel jPanel1Label2;
private javax.swing.JLabel jPanel1Label3;
private javax.swing.JPanel jPanel2;
private javax.swing.JPasswordField jPasswordField;
private javax.swing.JButton jRegister;
private javax.swing.JSeparator jSeparator1;
private javax.swing.JSeparator jSeparator2;
private javax.swing.JSeparator jSeparator3;
private javax.swing.JButton jSignIn;
private javax.swing.JCheckBox showPassword;
// End of variables declaration
}
答案 0 :(得分：1)
所有组件最终都需要添加到顶级容器（即Agra%20Public%20Institute%20of%20Technology%20&%20Computer%20Education,%20Artoni%20(Pharmacy)
）才能在屏幕上显示
有关详细信息，请查看How to Make Frames (Main Windows)
答案 1 :(得分：0)
是。最后完成了这个问题。 （尝试了很多方法）
刚刚更换了这一行：
public class loginPanel扩展了javax.swing.JPanel
用这个：
public class loginPanel扩展了javax.swing.JFrame
答案 2 :(得分：-1)
在主要课程中，你必须调用你的框架。
public static void main(String[] args) {
new loginpanel().setVisible(true);
}