2012-02-02 55 views
0

我發現了幾個有關該問題的問題並花費了一個小時,但仍然無法自己解決我的問題。我想要做的只是打開一個表單,並使用setText()更改jLabel1和jTextField1的值。以正確的方式更新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 
} 

的值不會在窗口中更新。我錯過了什麼?

回答

2

您的main - 類Main中的方法缺少static關鍵字,因此您無法運行此函數。

我假設你運行了main方法InfoWindow,它不叫Refresh


數點:

  • 你的組件(JLabelJTextField)應該宣佈static。您無法在窗口的實例之間共享它們。
    這將迫使你做出Refresh非靜態太
  • 更新在Event Dispatch Thread
  • Java的方法您的領域與小寫字母開始(的refresh代替Refresh

那怎麼你Main -class可能看起來像: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

實際上,'main'方法應該將所有這些都包含在可運行的EDT中。 – mre 2012-02-02 17:04:52

+0

@mre:你說得對,謝謝指出 – 2012-02-02 17:14:04

+0

非常感謝,它現在正在工作!你太棒了! :) – 2012-02-02 17:22:27

2
  1. 更新組件E事件分派線程
  2. 確保你調用一個名爲不佳Refresh方法上的一個實例的InfoWindow

我建議你Refresh非靜態方法和遵循Java的命名約定。還可以通過SwingUtilities.invokeLater在EDT中創建和修改組件。