Question

我正在尝试使用线程构建一个红绿灯信号量，但我无法正确。信号量应显示红色，黄色，绿色，颜色之间有间断。任何帮助深表感谢。谢谢。这是我的代码......

import java.awt.BorderLayout;
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class StopTheLights extends JFrame implements ActionListener {

    JButton start;
    JButton stop;
        JPanel panel;
    Boolean flag;

    public StopTheLights(String title) {
                Container c = getContentPane();

        start = new JButton("Start");
        stop = new JButton("Stop");

        start.addActionListener(this);
        stop.addActionListener(this);

        panel= new JPanel();
        panel.add(start);
        panel.add(stop);

        c.add(panel, BorderLayout.SOUTH);

        setSize(300, 450);                     
        setVisible(true);
        setLocation(200,200);

    }

    public void paint(Graphics g){
        super.paint(g);
        g.setColor(Color.black);
        g.drawOval(50,50,100,100);
        g.drawOval(50,155,100,100);
        g.drawOval(50,260,100,100);
    }

        public void actionPerformed(ActionEvent e){
        if(e.getSource() == start){
            flag = true;
            new ThreadExtend(this).start();
        }else{
            flag = false;
        }
    }
    public class ThreadExtend extends Thread {
        Graphics g;
        JFrame frame;

        public ThreadExtend(JFrame frame){
            this.frame = frame;
            g = frame.getGraphics();
        }
        public void run(){
            while(flag) {
                try{
                    paintRed(g);
                    if(!flag) {
                        break;
                    }
                    Thread.sleep(1000);
                    paintAmber(g);
                    if(!flag) {
                    break;
                    }
                    Thread.sleep(1000);
                    paintGreen(g);
                    if(!flag){
                        break;
                    }


                 }catch(InterruptedException e) {

               }
            }

        }

    }
    public void paintRed(Graphics g){
        g.setColor(new Color(255,0,0));
        g.fillOval(52, 52, 96, 96);
            g.fillOval(52, 52, 96, 96);
        g.fillOval(52, 262, 96, 96);

    }
    public void paintAmber(Graphics g){
        g.setColor(new Color(250,170,0));
        g.fillOval(52, 157, 96, 96);
            g.fillOval(52, 52, 96, 96);
        g.fillOval(52, 262, 96, 96);

    }
    public void paintGreen(Graphics g){
        g.setColor(new Color(0,250,0));
        g.fillOval(52, 262, 96, 96);
            g.fillOval(52, 52, 96, 96);
        g.fillOval(52, 157, 96, 96);

    }
         public static void main(String[] args) {
        new StopTheLights();

    }


}

Answer 1

这里有几个问题。

您的线程在显示绿灯后不会等待。
您可以在所有方法调用中绘制所有灯光，这是不需要的。
当＆＃34; 关闭＆＃34;时，你不会改变颜色。其他灯。

我在你的代码中做了一些修复，现在它可以工作了：

test.mp4

使用螺纹的红绿灯信号量

1 个答案: