Question

我正在使用java applet构建一个简单的赛车游戏，但它无法正常工作即使经过多次干运行，我也没有看到代码中的任何错误。为什么变量＆＃39; i＆＃39;我的代码没有增加......

 import java.awt.*;
 import java.awt.Dimension;
 import java.util.Random;
 import java.awt.event.*;
 import java.applet.*;
 import javax.swing.JApplet;
 import javax.swing.JOptionPane;
 /*
 <applet code= "car.class" height=1000 width=2000>
<param name="my" value="opp1_car.png">
<param name="you" value="opp2_car.png">

 </applet>
 */

 public class car extends Applet implements KeyListener,Runnable
 {  int x=0,y=0,x1=0,a=50,i=0;
Image car,car_opp;
int width,height,width_op1=0,width_op2=0;
Thread t;

public void init()
{   
    addKeyListener(this);
    setBackground(Color.gray);       
    this.requestFocus();
    Dimension dim=Toolkit.getDefaultToolkit().getScreenSize();
    width= (int)(dim.getWidth())/2;
    height=(int)dim.getHeight();                
}

public void paint(Graphics g)
{           
    g.setColor(Color.green);
    g.fillRect(0,0,600,1000);
    g.setColor(Color.green);
    g.fillRect(1400,0,600,1000);

    car_opp = getImage(getDocumentBase(),getParameter("you"));
    g.drawImage(car_opp,width+width_op1,i,this);            //      this is not moving 



    car = getImage(getDocumentBase(),getParameter("my"));    //     this moves on LEFT or RIGHT keyEvent
    g.drawImage(car,width+x,700,this);      

    String s="("+width_op1+",x="+x+",y="+y+")";
    g.setColor(Color.red);
    g.drawString(s,200,500);        
}

public void keyPressed(KeyEvent e) {

    int k=e.getKeyCode();
    switch(k)
    {
        case KeyEvent.VK_LEFT:  if(x>-360 ) x=x-20; break;

        case KeyEvent.VK_RIGHT: if( x<340 ) x=x+20; break;          
    }
repaint();      
}

public void start()
{
    t = new Thread();
    t.start();

}

public void run()
{   

    while(true)
    {   Random random= new Random();
        try
        {

            i=i+50;
            t.wait(100);

            if(i>1000)
            {
                i=100;
                width_op1=random.nextInt(340 + 360 + 1) -360;
                width_op2=random.nextInt(340 + 360 + 1) -360;
                width_op1=200;
            }           
            repaint();
        }
        catch(Exception e){}

        /*if((i>680&& i<780) && (x < width_op1+50 && x>width_op1-50))
        {
            System.exit(0);
        }*/
    }
}

public void keyReleased(KeyEvent e){}   
public void keyTyped(KeyEvent e){}



}

Answer 1

您误解了线程的工作原理。要在线程中运行Runnable，必须将其传递给构造函数，然后运行Thread。

试试这个：

public void start(){
    t = new Thread(this);
    t.start();

}

为什么是旗帜＆＃39;我＆＃39;我的代码没有增加

1 个答案: