Question

这项任务是为了模拟比赛＆＃39;两个跑步者用1（红色矩形）2（蓝色矩形）表示。当我点击开始按钮时，我应该使用线程来增加矩形的宽度，第一个达到屏幕宽度的是赢家。一切正常但除了一些未知的原因我不能让这些矩形出现。

HTML：

<HTML>
<BODY>
<APPLET CODE="AppletGame.class" WIDTH="300" HEIGHT="400">
</APPLET>
</BODY>
</HTML>

面板

//extends thread
//        thread contains the run(); method and sets rectangle specifics
import java.util.*;
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

 public class ThreadPanel extends JPanel
 {
//private Thread blueRunner =
private JLabel winnerLabel, gamelabel;
private int redWidth = 2, blueWidth = 2, x, y;
private JPanel board;
private Random generator = new Random();
private Thread RedRunner = new  RedRunner();
private Thread BlueRunner = new  BlueRunner();
  //Create a panel for the button and label
  //then create a pannel for the Rectangles(runners) to race
public ThreadPanel()
{
    winnerLabel = new JLabel ("Winner: ");
    winnerLabel.setBackground(Color.green);
    add(winnerLabel);

    setPreferredSize(new Dimension(300,360));
    setBackground (Color.white);
}

//graphics method to paint the shapes
public void PainComponent(Graphics g)
{
    //draws 2 seperate rectangles
    super.paintComponent(g);

    this.setBackground(Color.WHITE);

    g.setColor(Color.RED);
    g.fillRect(25, 100,redWidth, 2);

    g.setColor(Color.BLUE);
    g.fillRect(25, 100, blueWidth, 2);
 }
    //begins game and starts two threads
   public void startGame ()
   {
     RedRunner.start();
     BlueRunner.start();
   }

//create the threads that contain the (run method)
//x is the red runner, y for blue (to get random numbers)
class RedRunner extends Thread
{
    public RedRunner(){
    }

    public void run()
    {
        while(redWidth<=300)
        {
        x = generator.nextInt(6);
        redWidth+=x;
            if(redWidth==300 && blueWidth <300)
            {
            winnerLabel.setText("Winner: Red");
            }

        }
    }
}

//creates the second runner
class BlueRunner extends Thread
{
        public BlueRunner(){
        }

        public void run()
        {
          while(redWidth<300)
          {
          y = generator.nextInt(6);
          blueWidth+=y;
            if(redWidth<300 && blueWidth<300)
             {
                winnerLabel.setText( "Winner: Blue");
             }
          }

        }
}
}

最后是扩展JApplet的类：

 //#2
  //java file that extends JAPPLET which implements action listener
  //containts a button to start the game
  //containts instantiation of panel which contain the threads/runners
 //makes a rectangle object
  //IE constructs the objects
   import java.awt.*;
   import javax.swing.*;
   import java.awt.event.*;

  public class AppletGame extends JApplet implements ActionListener
  {
//applet that simulates 2 runners
   private final int BOARDWIDTH = 300, BOARDHEIGHT =400;

   private JButton startPlay;
   private ThreadPanel game;
   private String red = "Red", blue = "Blue";
   private int hits=0;

   private JPanel appletPanel, buttons;

   //-----------------------------------------------------------------
   //  Set up the components for the applet
   //-----------------------------------------------------------------
public void init()
{
    buttons = new JPanel();
    buttons.setOpaque(true);
    buttons.setPreferredSize(new Dimension(BOARDWIDTH, 40));
    buttons.setBackground(Color.white);

    startPlay = new JButton("Start Race");
    startPlay.setBackground(Color.cyan);

    startPlay.addActionListener(this);  //adds button listener for starting

    buttons.add(startPlay);

    game = new ThreadPanel();  //panel for the race portion of the applet

    appletPanel = new JPanel();
    appletPanel.add(buttons);//ands buttons and game panel to primary panel
    appletPanel.add(game);

    getContentPane().add(appletPanel);
      setSize(BOARDWIDTH, BOARDHEIGHT);     //sets size of primary panel

}

public void actionPerformed (ActionEvent event)
{
    String msg = "Race over Click to start again";
    if(event.getSource() == startPlay)
    {
        startPlay.setEnabled(false);
        game.startGame();
        repaint();
    }
}
}

Answer 1

注意拼写和大小写。请注意，您有：

public void PainComponent(Graphics g)

应该是：

public void paintComponent(Graphics g)

Java线程和小程序

1 个答案: