2012-02-02 29 views
0

我发现了几个有关该问题的问题并花费了一个小时,但仍然无法自己解决我的问题。我想要做的只是打开一个表单,并使用setText()更改jLabel1和jTextField1的值。以正确的方式更新jLabel和jTextField

Main.java:

package defaultpackage; 

public class Main { 
    public void main(String args[]) { 

     new InfoWindow().setVisible(true); 
     InfoWindow.Refresh("a", "b"); 
     } 
} 

InfoWindow.java:

package defaultpackage; 

public class InfoWindow extends javax.swing.JFrame { 
    public static void Refresh(String label, String textfield) { 
     jLabel1.setText(label); 
     jTextField1.setText(textfield); 
    } 
    public InfoWindow() { 
     initComponents(); 
    } 

    @SuppressWarnings("unchecked") 
    // <editor-fold defaultstate="collapsed" desc="Generated Code"> 
    private void initComponents() { 

     jLabel1 = new javax.swing.JLabel(); 
     jTextField1 = new javax.swing.JTextField(); 

     setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

     jLabel1.setText("jLabel1"); 

     jTextField1.setText("jTextField1"); 

     javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane()); 
     getContentPane().setLayout(layout); 
     layout.setHorizontalGroup(
      layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
      .addGroup(layout.createSequentialGroup() 
       .addContainerGap() 
       .addGroup(layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING, false) 
        .addComponent(jTextField1, javax.swing.GroupLayout.DEFAULT_SIZE, 179, Short.MAX_VALUE) 
        .addComponent(jLabel1, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) 
       .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) 
     ); 
     layout.setVerticalGroup(
      layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
      .addGroup(layout.createSequentialGroup() 
       .addContainerGap() 
       .addComponent(jLabel1) 
       .addPreferredGap(javax.swing.LayoutStyle.ComponentPlacement.RELATED) 
       .addComponent(jTextField1, javax.swing.GroupLayout.PREFERRED_SIZE, javax.swing.GroupLayout.DEFAULT_SIZE, javax.swing.GroupLayout.PREFERRED_SIZE) 
       .addContainerGap(javax.swing.GroupLayout.DEFAULT_SIZE, Short.MAX_VALUE)) 
     ); 

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

    public static void main(String args[]) { 

     //<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(InfoWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (InstantiationException ex) { 
      java.util.logging.Logger.getLogger(InfoWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (IllegalAccessException ex) { 
      java.util.logging.Logger.getLogger(InfoWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (javax.swing.UnsupportedLookAndFeelException ex) { 
      java.util.logging.Logger.getLogger(InfoWindow.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } 
     //</editor-fold> 

     java.awt.EventQueue.invokeLater(new Runnable() { 

      public void run() { 
       new InfoWindow().setVisible(true); 
      } 
     }); 

    } 
    // Variables declaration - do not modify 
    public static javax.swing.JLabel jLabel1; 
    public static javax.swing.JTextField jTextField1; 
    // End of variables declaration 
} 

的值不会在窗口中更新。我错过了什么?

回答

2

您的main - 类Main中的方法缺少static关键字,因此您无法运行此函数。

我假设你运行了main方法InfoWindow,它不叫Refresh


数点:

  • 你的组件(JLabelJTextField)应该宣布static。您无法在窗口的实例之间共享它们。
    这将迫使你做出Refresh非静态太
  • 更新在Event Dispatch Thread
  • Java的方法您的领域与小写字母开始(的refresh代替Refresh

那怎么你Main -class可能看起来像:在日

public class Main { 
    public static void main(String args[]) { 
     SwingUtilities.invokeLater(new Runnable() { 
      @Override 
      public void run() { 
       InfoWindow infoWindow = new InfoWindow(); 
       infoWindow.setVisible(true); 
       infoWindow.refresh("a", "b"); 
      } 
     }); 
    } 
} 
+0

实际上,'main'方法应该将所有这些都包含在可运行的EDT中。 – mre 2012-02-02 17:04:52

+0

@mre:你说得对,谢谢指出 – 2012-02-02 17:14:04

+0

非常感谢,它现在正在工作!你太棒了! :) – 2012-02-02 17:22:27

2
  1. 更新组件E事件分派线程
  2. 确保你调用一个名为不佳Refresh方法上的一个实例的InfoWindow

我建议你Refresh非静态方法和遵循Java的命名约定。还可以通过SwingUtilities.invokeLater在EDT中创建和修改组件。