Question

我的代码有问题。我使用各种JPanel创建了一个GUI，我将按钮放在JPanel中，将JTextArea放在JPanel中。当我点击按钮创建命令console.append（＆＃34;＆＃34;）;在控制台上显示消息将无法运行并告诉我：

线程中的异常＆＃34; AWT-EventQueue-0＆＃34;

单击按钮时，如何让我打印信息？如果它不起作用console.append

P.S。我知道问题是调用console.append（＆＃34;＆＃34;）;因为，例如，如果在构造函数中粘贴connect（）的内容就会被执行，但这对我不利

这是我的代码：

import java.awt.*;   
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.*;
import java.io.DataInputStream;
import java.io.DataOutputStream;
import javax.swing.*;
import javax.swing.JTextArea;
import lejos.pc.comm.*;


public class send {

    JPanel pan1;
    JPanel pan2;
    JPanel pan3;
    JPanel pan4;
    JPanel pan5;
    JButton reconnect;
    JButton disconnect;
    JButton start;
    JCheckBox show1;
    JLabel label1;
    JCheckBox show2;
    JLabel label2;
    JSlider sldCentigrade;
    JTextField txtCent;
    JSlider Luminosity;
    JTextField txtLum;


    JLabel img;
    DataOutputStream dos;
    DataInputStream dis;
    JFrame s;
    JTextArea console;
    JScrollPane pScroll;

    public static void main(String[] args) {

         send send = new send();

            send.connect();//Start connection
    }


    public  send(){

         s = new JFrame();

        s.setTitle("Server");
        s.setSize(550,650);
        s.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        s.setVisible(true);


        JPanel pan1= new JPanel();
        //pan1.setBackground(Color.GREEN);


        JPanel pan2= new JPanel();
        //pan2.setBackground(Color.MAGENTA);
        pan2.setLayout(new BorderLayout());

        JPanel pan3= new JPanel();
        //pan3.setBackground(Color.RED);
        pan3.setLayout(new BorderLayout());

        JPanel pan4= new JPanel();
        //pan4.setBackground(Color.BLUE);

        JPanel pan5= new JPanel();
        //pan5.setBackground(Color.YELLOW);
        pan5.setLayout(new BorderLayout());

        JTextArea console = new JTextArea();



        JButton reconnect = new JButton("Re/Connect");
        reconnect.setSize(50, 50);
        pan4.add(reconnect);
        reconnect.addActionListener(new reconnectListener());

        JButton disconnect = new JButton("Disconnect");
        disconnect.setSize(50,50);
        pan4.add(disconnect);
        disconnect.addActionListener(new disconnectListener());

        JButton start = new JButton("Start");
        start.setSize(50,50);
        pan4.add(start);
        start.addActionListener(new startListener());

        /*JButton reconnect = new JButton("Reconnect");
        start.setSize(50, 50);
        pan3.add(reconnect);

        JButton stop = new JButton("STOP");
        stop.setSize(50, 50);
        pan2.add(stop);

        JButton pause = new JButton("PAUSE");
        pause.setSize(50, 50);
        pan5.add(pause);
      */
        JCheckBox show1= new JCheckBox();
        pan1.add(show1,BorderLayout.NORTH);

        JLabel label1 = new JLabel("Automatic");
        pan1.add(label1);


        JCheckBox show2= new JCheckBox();
        pan1.add(show2,BorderLayout.CENTER);

        JLabel label2 = new JLabel("Manual");
        pan1.add(label2);

        JSlider sldCentigrade = new JSlider();
        sldCentigrade.setPreferredSize(new Dimension(280, 20));
        JTextField txtCent = new JTextField("Temperature");

        pan5.add(txtCent,BorderLayout.CENTER);
        pan2.add(sldCentigrade, BorderLayout.CENTER);



        JSlider Luminosity = new JSlider();
        JTextField txtLum = new JTextField("Luminosity");

        pan5.add(txtLum,BorderLayout.SOUTH);
        pan2.add(Luminosity,BorderLayout.SOUTH);


        JScrollPane pScroll = new JScrollPane(console, JScrollPane.VERTICAL_SCROLLBAR_ALWAYS, JScrollPane.HORIZONTAL_SCROLLBAR_ALWAYS);
        pScroll.setPreferredSize(new Dimension(600, 450));
        pan3.add(pScroll,BorderLayout.SOUTH);


        JLabel img= new JLabel();
        img.setIcon(new ImageIcon("C:\\Users\\TEX\\Desktop\\mindstorms.jpg"));
        img.setPreferredSize(new Dimension(50, 80));
        pan3.add(img,BorderLayout.NORTH);

        s.getContentPane().add(pan1,BorderLayout.WEST);
        s.getContentPane().add(pan2,BorderLayout.EAST);
        s.getContentPane().add(pan3,BorderLayout.NORTH);
        s.getContentPane().add(pan4,BorderLayout.SOUTH);
        s.getContentPane().add(pan5,BorderLayout.CENTER);
        //s.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        //s.setVisible(true);

    }


    public void connect()
    {

        NXTConnector conn = new NXTConnector();//create a new NXT connector
        boolean connected = conn.connectTo("btspp://"); //try to connect to any NXT over bluetooth


        if (!connected) {//failure
            JTextArea console = new JTextArea();
            console.append("Failed to connect to any NXT\n");
            console.append("Press Reconect to retry.\n");

        }

        else//success!
        {JTextArea console = new JTextArea();
        console.append("Connected to " + conn.getNXTInfo() + "\n");


        dos= new DataOutputStream (conn.getOutputStream ()); //create data input and output streams to send and recieve data.
        dis = new DataInputStream (conn.getInputStream ());
        }

    }
        public void disconnectAction()
        {


            try{
            dos.writeInt(0); //NXT recognizes 0 as command to terminate bluetooth connection and seek a new one.
            dos.flush();
            console.append("NXT disconnected. Press Reconnect to reconnect.\n");
            }
            catch(Exception e){console.append("Could not send command\n");}
        }


         public void startAction()
         {

             try{
                 dos.writeInt(39); //NXT recognizes 39 as command to start NXT.
                 dos.flush();
                 console.append("NXT is doing :.\n");
                 String s = dis.readLine();
                 console.append( s +"\n" ) ;//read from NXT
                 }
                 catch(Exception e){console.append("Could not send command\n");}


         }


         class disconnectListener implements ActionListener
         {
             public void actionPerformed(ActionEvent evt)
             {
                 disconnectAction();
             }
         }

           class reconnectListener implements ActionListener
         {
             public void actionPerformed(ActionEvent evt)
             {
                 connect();// call main connect method to try to connect again
             }
         }



           class startListener implements ActionListener 
           {
               public void actionPerformed(ActionEvent evt)
               {
                   startAction();
               }
           }


}

Answer 1

构建你的ui时，你隐藏了所有的类成员。而不是再次声明：

JPanel pan1= new JPanel();

只需分配给它：

pan1= new JPanel();

（这适用于所有班级成员）

线程中的异常＆＃34; AWT-EventQueue-0＆＃34;

1 个答案: