Question

我正在使用Ovals和Graphics对象在java中编写一个简单的游戏。它被称为病毒，其工作原理如下：中间有一个椭圆形，外面有六个椭圆形。这些外部椭圆应该增加尺寸直到被点击，当它们消失并且玩家得到10分时。如果椭圆形接触中央椭圆形，则中心椭圆形的健康状况会下降。当它达到零时，游戏结束。我遇到的问题是外部椭圆的尺寸不会增加。为什么会这样？

这是我的代码：

package virus;


import java.awt.*;
import java.util.Random;
import javax.swing.JPanel;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class VirusGamePanel extends JPanel implements MouseListener{
    private static final long serialVersionUID = 1L;//serialVersionUID field
    Random colour = new Random();//the outside ovals will always be a random colour
    private int sizeX = 1;//the x size of the outside ovals 
    private int sizeY = 1;//the y size of the outside ovals
    int score = 0;
    static String scorestring = "Score: ";
    Color rand = new Color(colour.nextInt(255),colour.nextInt(255),colour.nextInt(255));//generate the random colour

    public void paint(Graphics g)
    {
        super.paint(g);
        g.setColor(Color.magenta);
        g.drawString(scorestring+score,275,250);
        g.setColor(Color.orange);
        g.drawOval(200,150,200,200);
        g.setColor(rand);
        g.drawOval(270,50,50,50);
        g.drawOval(100,100,50,50);
        g.drawOval(450,100,50,50);
        g.drawOval(100,400,50,50);
        g.drawOval(450,400,50,50);
        g.drawOval(275,450,50,50);
        g.fillOval(270,50,sizeX,sizeY);//these six ovals are supposed to increase in size
        g.fillOval(100,100,sizeX,sizeY);
        g.fillOval(450,100,sizeX,sizeY);
        g.fillOval(100,400,sizeX,sizeY);
        g.fillOval(450,400,sizeX,sizeY);
        g.fillOval(275,450,sizeX,sizeY);
        inc();
    }

    public static void main(String[] args) {
      JPanel panel = new VirusGamePanel();

      JFrame frame = new JFrame("Virus");
      frame.setSize(700, 700);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(panel);
      frame.setVisible(true);
    }

    private void inc()//increase the size of the ovals
    {
        for(int i = 0; i<25000; i++)
        {
            sizeX++;
            sizeY++;
            repaint();
        }
    }

带线程的新代码：

package virus;


import java.awt.*;
import java.util.Random;
import javax.swing.JPanel;

import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;

public class VirusGamePanel extends JPanel implements MouseListener,Runnable{
    private static final long serialVersionUID = 1L;
    Random colour = new Random();
    private int sizeX = 1;
    private int sizeY = 1;
    int score = 0;
    Thread thr = new Thread();
    static String scorestring = "Score: ";
    Color rand = new Color(colour.nextInt(255),colour.nextInt(255),colour.nextInt(255));

    public void paint(Graphics g)
    {
        super.paint(g);
        thr.start();
        g.setColor(Color.magenta);
        g.drawString(scorestring+score,275,250);
        g.setColor(Color.orange);
        g.drawOval(200,150,200,200);
        g.setColor(rand);

        g.fillOval(270,50,sizeX,sizeY);
        g.fillOval(100,100,sizeX,sizeY);
        g.fillOval(450,100,sizeX,sizeY);
        g.fillOval(100,400,sizeX,sizeY);
        g.fillOval(450,400,sizeX,sizeY);
        g.fillOval(275,450,sizeX,sizeY);
        inc();
    }

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

    private void inc()
    {
        thr.run();
    }
    public void run(){
        for(int i = 0; i<25000; i++)
        {
            sizeX++;
            sizeY++;
            repaint();
            try
            {
                Thread.sleep(10);
            }
            catch(InterruptedException e)
            {
                e.printStackTrace();
            }
        }
    }

Answer 1

 for(int i = 0; i<25000; i++)
    {
        sizeX++;
        sizeY++;
        repaint();
    }

您的计算机无法像cpu增加sizeX和sizeY那样快速重绘。添加一些等待时间（以毫秒为单位）（特别是如果你绘制一个像800x600这样的大区域）

 for(int i = 0; i<25000; i++)
    {
        sizeX++;
        sizeY++;
        repaint();
        try{ sleep(100);} catch(InterruptedException e){}
    }

但是，从另一个线程做到这一点！那么，你的应用。不会冻结。

这是10 FPS。但你试过2G FPS。美好的一天。

以下是一个帖子的例子。

class TEN_FPS extends Thread
{
    public void run()
    {
        while(working)
        {
             //calculations here
             repaint();
             try{sleep(100);}catch(InterruptedException e){}
        }
     }
 }

然后在主要方法中：

working=true;
TEN_FPS.start();

完成此计划后：

working=false;

将释放您的守护程序线程。

Answer 2

您的代码是递归的。在inc（）中，你调用repaint，它调用VirusGamePanel.paint（），调用inc（）......

每次调用repaint（）都会重新调用paint（）方法。因此，不要在inc（）中循环执行此操作：

private void inc()// increase the size of the ovals
{
  sizeX++;
  sizeY++;
  repaint();
}

Answer 3

这对我有用：

public class VirusGamePanel extends JPanel{
    private static final long serialVersionUID = 1L;//serialVersionUID field
    Random colour = new Random();//the outside ovals will always be a random colour
    private int sizeX = 0;//the x size of the outside ovals 
    private int sizeY = 0;//the y size of the outside ovals
    int score = 0;
    static String scorestring = "Score: ";
    Color rand = new Color(colour.nextInt(255), colour.nextInt(255), colour.nextInt(255)); //generate the random colour

    public void paint(Graphics g)
    {
        super.paint(g);
        g.setColor(Color.magenta);
        g.drawString(scorestring+score,275,250);
        g.setColor(Color.orange);
        g.drawOval(200, 150, 200, 200);
        g.setColor(rand);
        g.fillOval(270 - sizeX / 2, 50 - sizeY / 2, sizeX, sizeY);//these six ovals are supposed to increase in size
        g.fillOval(100 - sizeX / 2,100 - sizeY / 2, sizeX, sizeY);
        g.fillOval(450 - sizeX / 2,100 - sizeY / 2, sizeX, sizeY);
        g.fillOval(100 - sizeX / 2,400 - sizeY / 2, sizeX, sizeY);
        g.fillOval(450 - sizeX / 2,400 - sizeY / 2, sizeX, sizeY);
        g.fillOval(275 - sizeX / 2,450 - sizeY / 2, sizeX, sizeY);
        inc();
    }

    public static void main(String[] args) {
      JPanel panel = new VirusGamePanel();

      JFrame frame = new JFrame("Virus");
      frame.setSize(700, 700);
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.getContentPane().add(panel);
      frame.setVisible(true);
    }

    private void inc()//increase the size of the ovals
    {
            sizeX++;
            sizeY++;
            repaint();
    }
}

修复椭圆的中心点并删除inc方法中的循环。如果要绘制椭圆边界，只需添加drawOval命令，其参数与fillOval命令相同。

修改：

如果您想减慢增长过程，只需在inc()方法的paint调用之前添加以下内容：

try { Thread.sleep(100); } catch (InterruptedException e) { e.printStackTrace(); }

绘制椭圆形的图形在java中不会增加

3 个答案: