无法将netbeans中的主类与其他类连接

Question

我想在netbeans中创建一个基于gui的应用程序，但是我的主类没有连接到其他类。 主类的代码如下：

package legaldiary; 
public class Main { 
public static void main(String[] args) { 
    // TODO code application logic here 
    ULogin ulgn = new ULogin(); 

} 
} 

其他类的代码如下：

package legaldiary; 
public class ULogin extends javax.swing.JFrame { 
public ULogin() { 
    initComponents(); 
} 
@SuppressWarnings("unchecked") 
// <editor-fold defaultstate="collapsed" desc="Generated Code"> 
private void initComponents() { 

    jLabel1 = new javax.swing.JLabel(); 
    jLabel2 = new javax.swing.JLabel(); 
    jLabel3 = new javax.swing.JLabel(); 
    jTextField1 = new javax.swing.JTextField(); 
    jTextField2 = new javax.swing.JTextField(); 
    jButton1 = new javax.swing.JButton(); 

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

    jLabel1.setText("Welcome to Legal Diary"); 

    jLabel2.setText("jLabel2"); 

    jLabel3.setText("jLabel3"); 

    jTextField1.setText("jTextField1"); 

    jTextField2.setText("jTextField2"); 

    jButton1.setText("jButton1"); 

    javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); 
    getContentPane().setLayout(layout); 
    layout.setHorizontalGroup(
     layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(layout.createSequentialGroup() 
      .addGap(64, 64, 64) 
      .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
       .addGroup(layout.createSequentialGroup() 
        .addComponent(jLabel2) 
        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 172, Short.MAX_VALUE) 
        .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) 
       .addGroup(layout.createSequentialGroup() 
        .addComponent(jLabel3) 
        .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 172, Short.MAX_VALUE) 
        .addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE))) 
      .addGap(71, 71, 71)) 
     .addGroup(layout.createSequentialGroup() 
      .addGap(89, 89, 89) 
      .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 174, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addContainerGap(137, Short.MAX_VALUE)) 
     .addGroup(layout.createSequentialGroup() 
      .addGap(152, 152, 152) 
      .addComponent(jButton1) 
      .addContainerGap(175, Short.MAX_VALUE)) 
    ); 
    layout.setVerticalGroup(
     layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(layout.createSequentialGroup() 
      .addGap(41, 41, 41) 
      .addComponent(jLabel1, javax.swing.GroupLayout.PREFERRED_SIZE, 50, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addGap(37, 37, 37) 
      .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) 
       .addComponent(jLabel2) 
       .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) 
      .addGap(57, 57, 57) 
      .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.BASELINE) 
       .addComponent(jLabel3) 
       .addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)) 
      .addGap(18, 18, 18) 
      .addComponent(jButton1) 
      .addContainerGap(34, Short.MAX_VALUE)) 
    ); 

    pack(); 
}// </editor-fold> 

/** 
* @param args the command line arguments 
*/ 
public static void main(String args[]) { 
    java.awt.EventQueue.invokeLater(new Runnable() { 
     public void run() { 
      new ULogin().setVisible(true); 
     } 
    }); 
} 

// Variables declaration - do not modify 
private javax.swing.JButton jButton1; 
private javax.swing.JLabel jLabel1; 
private javax.swing.JLabel jLabel2; 
private javax.swing.JLabel jLabel3; 
private javax.swing.JTextField jTextField1; 
private javax.swing.JTextField jTextField2; 
// End of variables declaration 

}

请帮我找到的错误。

Answer 1

您从未在您的Main课程中致电setVisible。

SwingUtilities.invokeLater(new Runnable() { 
    public void run() { 
     new ULogin().setVisible(true); 
    } 
});