在運行時在netbeans中創建組件

Question

所有這些雖然我正在使用可視化構建器進行設計。我想在運行時添加一些組件。我在設計時添加了一個jpanel。我想在運行時在jpanel上添加一個按鈕。這是我添加的代碼和代碼。我運行時該按鈕不可見。

/* 
* To change this template, choose Tools | Templates 
* and open the template in the editor. 
*/ 
package main; 

import javax.swing.JButton; 

/** 
    * 
* @author FirmView 
*/ 
public class NewJFrame extends javax.swing.JFrame { 

/** 
* Creates new form NewJFrame 
*/ 
public NewJFrame() { 
    initComponents(); 
} 

private void addGUIComponents(){ 
    JButton b = new JButton("Click Me"); 
    jPanel1.add(b); 
} 

/** 
* 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() { 

    jPanel1 = new javax.swing.JPanel(); 

    setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

    javax.swing.GroupLayout jPanel1Layout = new javax.swing.GroupLayout(jPanel1); 
    jPanel1.setLayout(jPanel1Layout); 
    jPanel1Layout.setHorizontalGroup(
     jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGap(0, 341, Short.MAX_VALUE) 
    ); 
    jPanel1Layout.setVerticalGroup(
     jPanel1Layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGap(0, 83, Short.MAX_VALUE) 
    ); 

    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(26, 26, 26) 
      .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addContainerGap(33, Short.MAX_VALUE)) 
    ); 
    layout.setVerticalGroup(
     layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
     .addGroup(layout.createSequentialGroup() 
      .addGap(41, 41, 41) 
      .addComponent(jPanel1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) 
      .addContainerGap(176, Short.MAX_VALUE)) 
    ); 

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

/** 
* @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(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
    } catch (InstantiationException ex) { 
     java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
    } catch (IllegalAccessException ex) { 
     java.util.logging.Logger.getLogger(NewJFrame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
    } catch (javax.swing.UnsupportedLookAndFeelException ex) { 
     java.util.logging.Logger.getLogger(NewJFrame.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() { 
      NewJFrame f = new NewJFrame(); 
      f.addGUIComponents(); 
      f.show(); 
     } 
    }); 
} 
// Variables declaration - do not modify 
private javax.swing.JPanel jPanel1; 
// End of variables declaration 

}

Answer 1

當你這樣的組件時，你必須事先調用revalidate()。

Answer 2

的問題是，你是在initComponent()創建的JPanel對象然後添加按鈕，將另一個的JPanel在addGUIComponents()

更好的對象使JPanel類一個Singleton ...所以你得到了相同的JPanel對象。