java - 为什么循环禁用其他按钮或 Swing 组件？

Question

当我按下其中包含 for 循环事件的 jbutton 时，其他组件被禁用。

这是我从 jbutton 获得的代码:

    try{
        InetAddress localhost = InetAddress.getLocalHost();
        byte[] ip = localhost.getAddress();

        for(int i=1;i<254;i++){
            ip[3]=(byte)i;
            final InetAddress address = InetAddress.getByAddress(ip);

            if(address.isReachable(1000)){
                listModel1.addElement(address);
                System.out.println(address + "-Machine is turned on and can be ping.");
                Rectangle progressRec = jProgressBar1.getBounds();
                progressRec.x = 0;
                progressRec.y = 0;
                jProgressBar1.setValue(i);
                jProgressBar1.paintImmediately(progressRec);
            }
        }
        jList1.setModel(listModel1);
    }catch(Exception e){
        e.printStackTrace();
    }

那么循环结束后，其他组件就启用了吗？我该如何处理呢？提前致谢...

编辑的代码:由不擅长编码的人建议

    try{
        InetAddress localhost = InetAddress.getLocalHost();
        final byte[] ip = localhost.getAddress();

        SwingWorker<ListModel, InetAddress> worker = new SwingWorker<ListModel, InetAddress>(){
            public ListModel doInBackground() throws UnknownHostException, IOException{
                for(int i=1;i<254;i++){
                    ip[3]=(byte)i;
                    final InetAddress address = InetAddress.getByAddress(ip);

                    if(address.isReachable(1000)){
                        publish(address);
                        listModel1.addElement(address);
                        Rectangle progressRec = jProgressBar1.getBounds();
                        progressRec.x = 0;
                        progressRec.y = 0;
                        jProgressBar1.setValue(i);
                        jProgressBar1.paintImmediately(progressRec);
                    }
                }
                return listModel1;
            }

            @Override
            public void process(List<InetAddress> addresses){//there was a problem here.
                for(InetAddress address : addresses){
                    System.out.println(address + "-Machine is turned on and can be ping.");
                }
            }

            @Override
             public void done(){
                try {
                    jList1.setModel(get());
                } catch (InterruptedException ex) {
                    Logger.getLogger(NetCafeTime.class.getName()).log(Level.SEVERE, null, ex);
                } catch (ExecutionException ex) {
                    Logger.getLogger(NetCafeTime.class.getName()).log(Level.SEVERE, null, ex);
                }
            }
         };
         worker.execute();
    }catch(Exception e){
        e.printStackTrace();
    }

Answer 1

大概，“禁用”意味着它们变得没有响应。

发生这种情况是因为您在 Event Dispatch Thread 中执行非常昂贵/长期的操作。它处理所有与 GUI 相关的操作，例如重新绘制组件。当您的代码阻塞此线程时，Swing 无法快速执行常规操作，并且 UI 将变得对用户操作无响应，并且绘画或绘制操作也可能出现滞后/卡住。

您应该生成一个新线程来完成繁重的工作并报告结果。 Swing 提供 SwingWorker可以帮助您做您想做的事情的类(class)。

快速而肮脏的代码:

try{
    InetAddress localhost = InetAddress.getLocalHost();
    final byte[] ip = localhost.getAddress();

    SwingWorker<ListModel, InetAddress> worker = new SwingWorker<ListModel, InetAddress>()
    {
        public ListModel doInBackground()
        {
            for(int i=1;i<254;i++){
                ip[3]=(byte)i;
                final InetAddress address = InetAddress.getByAddress(ip);

                if(address.isReachable(1000)){
                    publish(address);
                    listModel1.addElement(address);
                }
            }

            return listModel1;
        }

        public void process(List<InetAddress> addresses)
        {
            for(InetAddress address : addresses)
            {
                System.out.println(address + "-Machine is turned on and can be ping.");
                Rectangle progressRec = jProgressBar1.getBounds();
                progressRec.x = 0;
                progressRec.y = 0;
                jProgressBar1.setValue(i);
                jProgressBar1.paintImmediately(progressRec);
            }
        }

        public void done()
        {
            jList1.setModel(get());
        }
    };

    worker.execute();

}catch(Exception e){
    e.printStackTrace();
}

建议阅读:

• http://download.oracle.com/javase/tutorial/uiswing/concurrency/index.html
• http://java.sun.com/products/jfc/tsc/articles/threads/threads2.html
• http://java.sun.com/products/jfc/tsc/articles/threads/threads1.html