javax.swing.Timer的困難

Question

按對勾按鈕時出現運行時錯誤。 我試圖在按下對勾按鈕以觸發事件時使用javax.swing.Timer。因此，如果有人有任何建議，我將不勝感激。 我當前正在使用Eclipse，並且按下對勾按鈕時出現運行時錯誤。

線程“ AWT-EventQueue-0”中的異常java.lang.Error：未解決的編譯問題：ClockPanel類型必須在ClockPanel.actionPerformed（ClockPanel.java:10）處實現繼承的抽象方法ActionListener.actionPerformed（ActionEvent）

這是我正在使用的代碼（3個類）。

import java.util.Calendar;
import java.util.GregorianCalendar;

class Clock 
{
     int hour;
     int minute;
     int second;

     Calendar gregcal = new GregorianCalendar();
     int h = gregcal.get(Calendar.HOUR_OF_DAY);
     int m = gregcal.get(Calendar.MINUTE);
     int s = gregcal.get(Calendar.SECOND);

    //default constructor
    Clock()
    {
        hour = h;
        minute = m;
        second = s; 
    }

    //parameterized constructor
    Clock(int hour, int minute, int second)
    {
        this.hour = hour;
        this.minute = minute;
        this.second = second;      
    }

    public int getHour()
    {
        return hour;
    }

    public int getMinute()
    {
        return minute;
    }


    public int getSecond()
    {
        return second;
    }

    public String toString()
    {
        return "The time is: " + hour + ":" + minute + ":" + second ;    
    }   

    public void tick()
    {
        second += 1;
        if(second > 60)
        {
            second = 0;
            minute++;
        }
        if(minute > 60)
        {
            minute =0;
            hour++;
        }
        if(hour > 24)
        {
            hour = 0;
        }
        System.out.println(this.toString());
    }
}

// next class


import java.awt.*;
import java.util.Calendar;
import java.util.GregorianCalendar;

import javax.swing.*;

public class TestClock 
{
    public static void main(String[] args)
    {
        Calendar gregcal = new GregorianCalendar();
        int h = gregcal.get(Calendar.HOUR_OF_DAY);
        int m = gregcal.get(Calendar.MINUTE);
        int s = gregcal.get(Calendar.SECOND);

        Clock c = new Clock(h, m, s);

        JFrame application = new JFrame("Clock");
        ClockPanel panel = new ClockPanel(c);

        application.add(panel);
        application.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        application.setSize(160,80);
        application.setVisible(true);  
    }

}


// the last class here is the problem
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.JLabel;
import javax.swing.JButton;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.Timer;

class ClockPanel extends JPanel implements ActionListener
{
    Clock myck = new Clock();
    private javax.swing.Timer timer;
    JTextField txt1, txt2, txt3;
    JLabel  jl1, jl2;
    JButton tick;
    JPanel top, buttom;



    ClockPanel(Clock ck)
    {

        this.setLayout(new GridLayout(2,1));
        top = new JPanel();
        top.setLayout(new GridLayout(1,5));

        String hour  = "" + ck.getHour(); // easier way  
        txt1 = new JTextField(hour);
        top.add(txt1);

        jl1 = new JLabel(" : ");
        top.add(jl1);

        String minute = Integer.toString(ck.getMinute()); // harder convertion
        txt2 = new JTextField(minute);
        top.add(txt2);

        jl2 = new JLabel(" : ");
        top.add(jl2);

        String second = Integer.toString(ck.getSecond());
        txt3 = new JTextField(second);
        top.add(txt3);
        this.add(top);


        buttom = new JPanel(new GridLayout(1,1));


        tick = new JButton("tick");
        buttom.add(tick);
        tick.addActionListener(this);
        this.add(buttom);

    }

    javax.swing.Timer t = new javax.swing.Timer(1000, new ActionListener() {



    public void actionPerformed(ActionEvent ae) 
    {

        if(ae.getSource().equals(tick))
        {

            myck.tick();
            txt1.setText(Integer.toString(myck.getHour()));
            txt2.setText(Integer.toString(myck.getMinute()));
            txt3.setText(Integer.toString(myck.getSecond()));   
        }   
    }
    });
    public void start()
    {
        t.start();
    }
}

Answer 1

根據我的評論，您的問題是您必須給ClockPanel類一個actionPerformed方法，該方法在此類的范圍內。 您甚至不應該嘗試運行無法編譯的類，而應該在嘗試運行代碼之前首先修復所有編譯錯誤。