title: Why is my JFrame blank?
body: <p>I'm really going crazy with this code. I need to know what im doing wrong? I'm supposed to get 3 textfields and one textarea showing and when I execute I just get one grey box. I cannot see the textfields and the textarea, not even the button. What is wrong? Why is my JFrame blank?! thanks</p>
  
  <p>Here is my code:</p>
  
  <pre><code>import javax.swing.JFrame;
  import javax.swing.JPanel;
  import javax.swing.JTextArea;
  import javax.swing.JTextField;
  import java.lang.Integer;
  
  
  
  public class MinVara extends javax.swing.JFrame {
  
      //Skapar upp instans variabler (instansvariabler in the body of the class
      //but outside the bodies of the class methods
  
    private String namn;
    private int nummer;
   private double pris; 
  
  
  
      //Skapar konstruktor för minvara.Like amethod, a constructor’s parameterlist 
   //specifies the data it requires to perform its task
   //An important difference between constructors and methods is that constructors
  //cannot return values, so they cannot specify a return type 
   //(not even void). Normally, constructors are declared public.
  
   public MinVara(String namn, int nummer, double pris) { 
          this.namn = namn; //this "Det här objektet name"
          this.nummer = nummer; //"" 
          this.pris = pris;//""
  
         // slut constructor 
          initComponents();
       }
  
  
  
      //Skapa ett nytt minvara objekt genom att kalla på en konstruktor
       MinVara var = new MinVara(namn, nummer, pris); //
  
  
      @Override
  public void setName(String namn)  {  
          this.namn = namn; } //store the string name
  
   public void setAntal (int nummer)  {  
          this.nummer = nummer;  }
  
      public void  setPrice (double pris) { 
          this.pris = pris; } 
  
  
  
      @Override
      public String getName() {    
          return this.namn;} 
  
  
      public int getAntal() {    
          return this.nummer; }     
  
      public double getPrice() {   
          return this.pris; } 
  
  
      /**
       * 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")
      // &lt;editor-fold defaultstate="collapsed" desc="Generated Code"&gt;                          
      private void initComponents() {
  
          jColorChooser1 = new javax.swing.JColorChooser();
          jColorChooser2 = new javax.swing.JColorChooser();
          jPanel1 = new javax.swing.JPanel();
          jScrollPane1 = new javax.swing.JScrollPane();
          jTextArea1 = new javax.swing.JTextArea();
          jTextField1 = new javax.swing.JTextField();
          jTextField2 = new javax.swing.JTextField();
          jTextField3 = new javax.swing.JTextField();
          jButton1 = new javax.swing.JButton();
          jLabel1 = new javax.swing.JLabel();
          jLabel2 = new javax.swing.JLabel();
          jLabel3 = new javax.swing.JLabel();
  
          setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
  
          jTextArea1.setColumns(20);
          jTextArea1.setRows(5);
          jScrollPane1.setViewportView(jTextArea1);
  
          jTextField2.addActionListener(new java.awt.event.ActionListener() {
              public void actionPerformed(java.awt.event.ActionEvent evt) {
                  jTextField2ActionPerformed(evt);
              }
          });
  
          jButton1.setText("OK");
          jButton1.addActionListener(new java.awt.event.ActionListener() {
              public void actionPerformed(java.awt.event.ActionEvent evt) {
                  jButton1ActionPerformed(evt);
              }
          });
  
          jLabel1.setText("Namn");
  
          jLabel2.setText("Pris");
  
          jLabel3.setText("Antal");
  
          javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1);
          jPanel1.setLayout(jPanel1Layout);
          jPanel1Layout.setHorizontalGroup(
              jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
              .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, jPanel1Layout.createSequentialGroup()
                  .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                      .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
                      .addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
                      .addComponent(jLabel2)
                      .addComponent(jLabel3)
                      .addComponent(jLabel1)
                      .addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, 90, javax.swing.GroupLayout.PREFERRED_SIZE)
                      .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 67, javax.swing.GroupLayout.PREFERRED_SIZE))
                  .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED, 44, Short.MAX_VALUE)
                  .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 239, javax.swing.GroupLayout.PREFERRED_SIZE)
                  .addGap(27, 27, 27))
          );
          jPanel1Layout.setVerticalGroup(
              jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
              .addGroup(jPanel1Layout.createSequentialGroup()
                  .addGroup(jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
                      .addGroup(jPanel1Layout.createSequentialGroup()
                          .addContainerGap()
                          .addComponent(jScrollPane1, javax.swing.GroupLayout.PREFERRED_SIZE, 249, javax.swing.GroupLayout.PREFERRED_SIZE))
                      .addGroup(jPanel1Layout.createSequentialGroup()
                          .addComponent(jLabel1)
                          .addGap(8, 8, 8)
                          .addComponent(jTextField2, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                          .addGap(18, 18, 18)
                          .addComponent(jLabel2)
                          .addGap(8, 8, 8)
                          .addComponent(jTextField3, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                          .addGap(18, 18, 18)
                          .addComponent(jLabel3)
                          .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.UNRELATED)
                          .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE)
                          .addGap(37, 37, 37)
                          .addComponent(jButton1, javax.swing.GroupLayout.PREFERRED_SIZE, 33, javax.swing.GroupLayout.PREFERRED_SIZE)))
                  .addContainerGap(40, Short.MAX_VALUE))
          );
  
          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)
          );
          layout.setVerticalGroup(
              layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
              .addComponent(jPanel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)
          );
  
          pack();
      }// &lt;/editor-fold&gt;                        
  
      private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {                                         
  
   jTextArea1.setText(null); //tömmer textarean
  
  //variablar till textfälten. omvandla string till int och double.
   this.namn =  jTextField1.getText();
   var.setName(namn);
   jTextArea1.append("Namnet på varan : " +var.getName());
  
   this.nummer  = Integer.parseInt( jTextField3.getText() );
  var.setAntal(nummer);
   jTextArea1.append("Antal varor : " + var.getAntal() );
  
   this.pris = Double.parseDouble(jTextField2.getText() );
   var.setPrice(pris);
   jTextArea1.append("Pris : " + var.getPrice());
  
  
  
  
  
  
  
      }                                        
  
      private void jTextField2ActionPerformed(java.awt.event.ActionEvent evt) {                                            
  
      }                                           
  
      /**
       * @param args the command line arguments
       */
      public static void main(String args[]) {
          /*
           * Set the Nimbus look and feel
           */
          //&lt;editor-fold defaultstate="collapsed" desc=" Look and feel setting code (optional) "&gt;
          /*
           * 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(MinVara.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
          } catch (InstantiationException ex) {
              java.util.logging.Logger.getLogger(MinVara.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
          } catch (IllegalAccessException ex) {
              java.util.logging.Logger.getLogger(MinVara.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
          } catch (javax.swing.UnsupportedLookAndFeelException ex) {
              java.util.logging.Logger.getLogger(MinVara.class.getName()).log(java.util.logging.Level.SEVERE, null, ex);
          }
          //&lt;/editor-fold&gt;
  
          /*
           * Create and display the form
           */
          java.awt.EventQueue.invokeLater(new Runnable() {
              @Override
              public void run() {
              JFrame frame = new JFrame("Resultat");
              JPanel jPanel1 = new JPanel();
  
              frame.getContentPane().add(jPanel1);
              frame.pack();
  
         frame.setSize(400,400);
            frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setVisible(true);
  
              }
          });
      }
      // Variables declaration - do not modify                     
      private javax.swing.JButton jButton1;
      private javax.swing.JColorChooser jColorChooser1;
      private javax.swing.JColorChooser jColorChooser2;
      private javax.swing.JLabel jLabel1;
      private javax.swing.JLabel jLabel2;
      private javax.swing.JLabel jLabel3;
      private javax.swing.JPanel jPanel1;
      private javax.swing.JScrollPane jScrollPane1;
      private javax.swing.JTextArea jTextArea1;
      private javax.swing.JTextField jTextField1;
      private javax.swing.JTextField jTextField2;
      private javax.swing.JTextField jTextField3;
      // End of variables declaration                   
  }
  </code></pre>