用第二个线程停止主线程

Question

我有一个Java线程的问题。 假设我们有一个名为Main的主线程和一个名为Frame的第二线程。此外，Frame还有一个JButton。在Main中，我们有一个只要在JFrame中按下按钮就会运行的循环。

我写了一个简短的例子为此，第一帧类别：

public class Frame extends javax.swing.JFrame{ 

    private boolean isRunning; 

    public Frame() { 
     initComponents(); 
     isRunning = true; 
    } 

    private void jButton1ActionPerformed(java.awt.event.ActionEvent evt) {           
     // TODO add your handling code here: 
     isRunning = false; 
    }           

    public boolean isRunning(){ 
     return isRunning; 
    } 

    // ***** Some netbeans stadard stuff ***** 
    /** 
    * 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() { 

     jButton1 = new javax.swing.JButton(); 

     setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE); 

     jButton1.setText("Stop"); 
     jButton1.addActionListener(new java.awt.event.ActionListener() { 
      public void actionPerformed(java.awt.event.ActionEvent evt) { 
       jButton1ActionPerformed(evt); 
      } 
     }); 

     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(167, 167, 167) 
       .addComponent(jButton1) 
       .addContainerGap(178, Short.MAX_VALUE)) 
     ); 
     layout.setVerticalGroup(
      layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING) 
      .addGroup(javax.swing.GroupLayout.Alignment.TRAILING, layout.createSequentialGroup() 
       .addContainerGap(153, Short.MAX_VALUE) 
       .addComponent(jButton1) 
       .addGap(124, 124, 124)) 
     ); 

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



    public void main() { 
     /* 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(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (InstantiationException ex) { 
      java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (IllegalAccessException ex) { 
      java.util.logging.Logger.getLogger(Frame.class.getName()).log(java.util.logging.Level.SEVERE, null, ex); 
     } catch (javax.swing.UnsupportedLookAndFeelException ex) { 
      java.util.logging.Logger.getLogger(Frame.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() { 
       new Frame().setVisible(true); 
      } 
     }); 
    } 

    // Variables declaration - do not modify      
    private javax.swing.JButton jButton1; 
    // End of variables declaration     

    // ***** End of this netbeans stuff ***** 
} 

现在主类

public class Main { 
    /** 
    * @param args the command line arguments 
    */ 
    public static void main(String[] args) { 
     Frame f = new Frame(); 
     f.main(); 

     for (int i = 0; f.isRunning(); i++) { 
      System.out.println((i + 1)); 
      try { 
       Thread.sleep(1000); 
      } catch (InterruptedException ex) { 
       Logger.getLogger(Main.class.getName()).log(Level.SEVERE, null, ex); 
      } 
     } 
    } 
} 

但是，如果我按下按钮，没有任何反应。我也试图与“实现Runnable”扩展该类框架和覆盖了的run（） - 方法，并开始在此主：

Thread t = new Thread(new Frame()); 
    t.start(); 

，但我得到了同样的问题。

请问，有人可以帮助我吗？

问候马蒂亚斯

Answer 1

你没有显示正确的Frame！

在Main您要创建一个新的Frame实例...

public class Main { 
    public static void main(String[] args) { 
     Frame f = new Frame(); 
     f.main(); 

     for (int i = 0; f.isRunning(); i++) { 
      // ... 
     } 
    } 
} 

，然后在Frame你创建另一个一个...

public class Frame extends javax.swing.JFrame{ 
    // ... 

    public void main() { 
     // ...   
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       new Frame().setVisible(true); 
      } 
     }); 
    } 

    // ... 
} 

的Frame你”已在您的Main课程中创建的课程不是正在显示的课程，这就是为什么f.isRunning()始终返回true。你可以通过显示正确的帧来解决这个问题：

public class Frame extends javax.swing.JFrame{ 
    // ... 

    public void main() { 
     // ...   
     Frame ref = this; 
     java.awt.EventQueue.invokeLater(new Runnable() { 
      public void run() { 
       ref.setVisible(true); 
      } 
     }); 
    } 

    // ... 
}