Question

问题是设计并实施一个绘制红绿灯并使用按钮来改变灯光的应用程序。从JPanel类派生绘图表面，并使用另一个面板来组织绘图表面和按钮。

我尝试过它并想出一个类来运行它，但我不确定如何运行它的main方法。

以下是代码：

import java.awt.*;
import java.awt.event.*;
import javax.swing.JPanel;
import java.applet.*;

public class TrafficLight extends JPanel implements ActionListener {

private Button lightRed, lightYellow, lightGreen;
private JPanel panel1;
private boolean lightRedClicked = false, lightYellowClicked = false, lightGreenClicked = false;

public void init() {

    setLayout(new BorderLayout());
    panel1 = new JPanel();

    lightGreen = new Button("Go");
    lightYellow = new Button("Wait");
    lightRed = new Button("Stop");
    panel1.add(lightRed);
    panel1.add(lightYellow);
    panel1.add(lightGreen);

    add(panel1, BorderLayout.NORTH);
}
public void paint(Graphics g){
    setBackground(Color.cyan);
    g.setColor(Color.black);
    g.fillRect(260,50,80,160);
    g.setColor(Color.black);
    g.fillRect(140,50,80,160);

    if(lightRedClicked == true){           
        g.setColor(Color.red);
        g.fillOval(280,60,40,40);
        g.setColor(Color.black);
        g.fillOval(280,110,40,40);
        g.fillOval(280,160,40,40);
        lightRedClicked = false;
    }
    if(lightYellowClicked == true) {
        g.setColor(Color.yellow);
        g.fillOval(280,110,40,40);
        g.setColor(Color.black);
        g.fillOval(280,60,40,40);
        g.fillOval(280,160,40,40);
        lightYellowClicked = false;
    }

    if(lightGreenClicked == true) {
        g.setColor(Color.green);
        g.fillOval(280,160,40,40);
        g.setColor(Color.black);
        g.fillOval(280,110,40,40);
        g.fillOval(280,60,40,40);
        lightGreenClicked = false;
    }
}
public void actionPerformed(ActionEvent swicth) {  
    if(swicth.getSource() == lightGreen){
    lightGreenClicked = true;
    repaint();
    }
    if(swicth.getSource() == lightYellow){
    lightYellowClicked = true;
    repaint();
    }
    if(swicth.getSource() == lightRed){
    lightRedClicked = true;
    repaint();
    }
}

}

Answer 1

试试这个

        public class JavaApplication5 {

    public static void main(String[] args) {
JFrame f = new JFrame("Traffic Light");
f.add(new TrafficLight());
f.setSize(500, 500);
f.setVisible(true);
    }
}

 class TrafficLight extends JPanel implements ActionListener {

   private Button lightRed, lightYellow, lightGreen;
private JPanel panel1;
private boolean lightRedClicked = false, lightYellowClicked = false, lightGreenClicked = false;
public TrafficLight(){
    setLayout(new BorderLayout());
    panel1 = new JPanel();

    lightGreen = new Button("Go");
    lightYellow = new Button("Wait");
    lightRed = new Button("Stop");
    panel1.add(lightRed);
    panel1.add(lightYellow);
    panel1.add(lightGreen);

    add(panel1, BorderLayout.NORTH);
    lightRed.addActionListener(this);
     lightGreen.addActionListener(this);
      lightYellow.addActionListener(this);
}
public void init() {


}
public void paint(Graphics g){
    setBackground(Color.cyan);
    g.setColor(Color.black);
    g.fillRect(260,50,80,160);
    g.setColor(new Color(255, 150, 150));     //light red
    g.fillOval(280,60,40,40);
    g.setColor(new Color(255, 255, 200));     //light yellow
    g.fillOval(280,110,40,40);
    g.setColor(new Color(150, 200, 150));      //light green
    g.fillOval(280,160,40,40);

    if(lightRedClicked == true){           
        g.setColor(Color.red);
        g.fillOval(280,60,40,40);
        lightRedClicked = false;
    }
    if(lightYellowClicked == true) {
        g.setColor(Color.yellow);
        g.fillOval(280,110,40,40);
        lightYellowClicked = false;
    }

    if(lightGreenClicked == true) {
        g.setColor(Color.green);
        g.fillOval(280,160,40,40);
        lightGreenClicked = false;
    }
}
public void actionPerformed(ActionEvent swicth) {  
    if(swicth.getSource() == lightGreen){
    lightGreenClicked = true;
    repaint();
    }
    if(swicth.getSource() == lightYellow){
    lightYellowClicked = true;
    repaint();
    }
    if(swicth.getSource() == lightRed){
    lightRedClicked = true;
    repaint();
    } 
}


}

制作并实现一个使用JPanel类制作交通信号灯的程序。

1 个答案: