Question

然后向JList模型添加元素只有奇怪的行为。在调用addElement（）方法时，列表变为空白，添加巨大的空元素或者将新元素向下移动几行。对方法的另一个要求是在问题出现之前和之后将其与所有元素一起转回，包括由＆＃34;不稳定＆＃34;添加的项目。呼叫。首先它似乎是绘画问题，只是重新调用没有帮助，只有添加新元素才能解决问题。

发生问题然后添加部分元素，不同启动涉及相同的索引。从未见过它很快就会在第一个索引上失败。

package r;

import java.io.IOException;
import java.net.InetAddress;
import java.net.ServerSocket;
import java.net.Socket;
import javax.swing.DefaultListModel;
import javax.swing.JOptionPane;


public class R extends javax.swing.JFrame {

    ServerSocket serverport;

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

    /**
     * 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() {

        scrollDebug = new javax.swing.JScrollPane();
        debugList = new javax.swing.JList();

        setDefaultCloseOperation(javax.swing.WindowConstants.EXIT_ON_CLOSE);
        setTitle("Debug");
        addWindowListener(new java.awt.event.WindowAdapter() {
            public void windowOpened(java.awt.event.WindowEvent evt) {
                formWindowOpened(evt);
            }
        });

        scrollDebug.setAutoscrolls(true);

        debugList.setSelectionMode(javax.swing.ListSelectionModel.SINGLE_SELECTION);
        scrollDebug.setViewportView(debugList);

        javax.swing.GroupLayout layout = new javax.swing.GroupLayout(getContentPane());
        getContentPane().setLayout(layout);
        layout.setHorizontalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(scrollDebug, javax.swing.GroupLayout.Alignment.TRAILING, javax.swing.GroupLayout.DEFAULT_SIZE, 682, Short.MAX_VALUE)
        );
        layout.setVerticalGroup(
            layout.createParallelGroup(javax.swing.GroupLayout.Alignment.LEADING)
            .addComponent(scrollDebug, javax.swing.GroupLayout.DEFAULT_SIZE, 383, Short.MAX_VALUE)
        );

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

    private void formWindowOpened(java.awt.event.WindowEvent evt) {                                  
        new Thread() {

            @Override
            public void run() {

                try {
                    serverport = new ServerSocket(33002, 0, InetAddress.getLoopbackAddress());

                    debugList.setModel(new DefaultListModel());

                    while (R.this.isVisible()) {
                        new ClientConnection(serverport.accept()).start();

                    }

                } catch (IOException ex) {
                    JOptionPane.showMessageDialog(null, "Error opening server port", "Debug", JOptionPane.ERROR_MESSAGE);
                }
            }

        }.start();


    }                                 

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

    class ClientConnection extends Thread {
        Socket connection;
        public ClientConnection(Socket connection){
            this.connection=connection;
        }


        @Override
        public void run() {
            try {


                connection.getOutputStream().write(String.format("debug>").getBytes());
                connection.getOutputStream().flush();

                String response = "";
                do {
                    response += (char) connection.getInputStream().read();
                } while (!response.endsWith(System.lineSeparator()));
                response = response.replace(System.lineSeparator(), "");

                ((DefaultListModel) debugList.getModel()).addElement(response);

                if (((DefaultListModel) debugList.getModel()).getSize() > 0) {
                    //debugList.ensureIndexIsVisible(((DefaultListModel) debugList.getModel()).getSize() - 1);
                    debugList.setSelectedIndex(((DefaultListModel) debugList.getModel()).getSize() - 1);
                    scrollDebug.getVerticalScrollBar().setValue(scrollDebug.getVerticalScrollBar().getMaximum());

                }

                connection.close();
            } catch (IOException ex) {
                JOptionPane.showMessageDialog(null, "Error receiving connection", "Debug", JOptionPane.ERROR_MESSAGE);
            }
        }

    }
    // Variables declaration - do not modify                     
    private javax.swing.JList debugList;
    private javax.swing.JScrollPane scrollDebug;
    // End of variables declaration                   
}

现在添加完整的示例代码。很抱歉给您带来不便！

Answer 1

这是用于创建接收数据并将字符串添加到JList的新线程的框架的内部类。

需要在事件调度线程上更新Swing组件，以便您无法直接在线程中更新组件。

因此，您可以在SwingUtilities.invokeLater(...)

中包装更新模型的代码

或者您可以使用SwingWorker和＆＃34;发布＆＃34;而不是使用单独的主题。结果，因为它们可用。

阅读Concurrency上Swing教程中的部分，了解有关这些概念和工作示例的更多信息。

Java JList Model addElement（）打破了列表的可视化表示

1 个答案: