-5

我正在做一些项目，其中的一部分——数字时钟。我希望那个时间像：17:3:5 会显示为 17:03:05。我的代码在下面（工作）。但是它有一些问题：我不确定我是否使用了正确的计时器，而且我的程序看起来很复杂，也许你可以帮助简化代码或提供一些想法如何以简单的方式编写它，谢谢。

import java.awt.Color;
import java.awt.Dimension;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.Calendar;

import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.Timer;
import javax.swing.WindowConstants;

public class SimpleDigitalClock {

    public static void main(String[] args) {

        JFrame f = new JFrame();
        f.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);
        DigitalClock myClock = new DigitalClock();
        f.add(myClock);
        f.pack();
        f.setVisible(true);
    }

    static class DigitalClock extends JPanel {

        String stringTime;
        int hour, minute, second;

        String correctionHour = "";
        String correctionMinute = "";
        String correctionSecond = "";

        public void setStringTime(String xyz) {
            this.stringTime = xyz;
        }

        public int findMinimumBetweenTwoNumbers(int a, int b) {
            return (a <= b) ? a : b;
        }

        DigitalClock() {

            Timer t1 = new Timer(1000, new ActionListener() {
                public void actionPerformed(ActionEvent e) {

                    repaint();
                }
            });
            t1.start();
        }

        @Override
        public void paintComponent(Graphics g) {
            super.paintComponent(g);

            Calendar now = Calendar.getInstance();
            hour = now.get(Calendar.HOUR_OF_DAY);
            minute = now.get(Calendar.MINUTE);
            second = now.get(Calendar.SECOND);

            if (hour < 10) {
                this.correctionHour = "0";
            }
            if (hour >= 10) {
                this.correctionHour = "";
            }

            if (minute < 10) {
                this.correctionMinute = "0";
            }
            if (minute >= 10) {
                this.correctionMinute = "";
            }

            if (second < 10) {
                this.correctionSecond = "0";
            }
            if (second >= 10) {
                this.correctionSecond = "";
            }
            setStringTime(correctionHour + hour + ":" + correctionMinute+ minute + ":" + correctionSecond + second);
            g.setColor(Color.BLACK);
            int length = findMinimumBetweenTwoNumbers(this.getWidth(),this.getHeight());
            Font myFont = new Font("SansSerif", Font.PLAIN, length / 5);
            g.setFont(myFont);
            g.drawString(stringTime, (int) length/6, length/2);

        }

        @Override
        public Dimension getPreferredSize() {
            return new Dimension(200, 200);
        }

    }

}
4

3 回答 3

3

格式化日期是SimpleDateFormat设计的目的：

DateFormat format = new SimpleDateFormat("hh:mm:ss");
String stringTime = format.format(new Date());
于 2012-12-27T17:26:12.090 回答
1

其他答案已评论您的代码的其他部分。

要居中显示，您可以使用以下绘图代码。

        g.setColor(Color.BLACK);
        int length = Math.min(this.getWidth(), this.getHeight());
        Font myFont = new Font("SansSerif", Font.PLAIN, length / 5);
        g.setFont(myFont);
        Graphics2D g2d = (Graphics2D) g;
        FontMetrics fm = g2d.getFontMetrics();
        Rectangle2D r = fm.getStringBounds(stringTime, g2d);
        int x = (this.getWidth() - (int) r.getWidth()) / 2;
        int y = this.getHeight() / 2;
        g.drawString(stringTime, x, y);
于 2012-12-27T17:44:15.850 回答
0

完整的修改类：

static class DigitalClock extends JPanel {

    String stringTime;

    public void setStringTime(String xyz) {
        this.stringTime = xyz;
    }

    public int findMinimumBetweenTwoNumbers(int a, int b) {
        return (a <= b) ? a : b;
    }

    DigitalClock() {

        Timer t1 = new Timer(1000, new ActionListener() {
            public void actionPerformed(ActionEvent e) {

                repaint();
            }
        });
        t1.start();
    }

    @Override
    public void paintComponent(Graphics g) {
        super.paintComponent(g);

        Calendar now = Calendar.getInstance();
        int hour = now.get(Calendar.HOUR_OF_DAY);
        int minute = now.get(Calendar.MINUTE);
        int second = now.get(Calendar.SECOND);

        String correctionHour = (hour < 10) ? "0" : "":
        String correctionMinute = (minute < 10) ? "0" : "";
        String correctionSecond = (second < 10) ? "0" : "";
        setStringTime(correctionHour + hour + ":" + correctionMinute+ minute + ":" + correctionSecond + second);
        g.setColor(Color.BLACK);
        int length = findMinimumBetweenTwoNumbers(this.getWidth(),this.getHeight());
        Font myFont = new Font("SansSerif", Font.PLAIN, length / 5);
        g.setFont(myFont);
        g.drawString(stringTime, (int) length/6, length/2);
    }

    @Override
    public Dimension getPreferredSize() {
        return new Dimension(200, 200);
    }
}

}

于 2012-12-27T17:30:11.207 回答