JAVA学习之GUI：贪吃蛇

这是根据“狂神说JAVA”的学习下编写的贪吃蛇程序，并在基础上解决了一些小问题：

  1. 解决了食物会出现在身体里的问题。
  2. 解决了可以后退的问题。

主程序 test.java

import javax.swing.*;

//游戏的主启动类
public class test {
    public static void main(String[] args) {
        JFrame frame = new JFrame();

        frame.setBounds(10,10,900,720);
        frame.setResizable(false);//窗口大小不可变
        frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);//窗口关闭
        //正常游戏界面都应该在面板上！
        frame.add(new Panel());


        frame.setVisible(true);//设置面板可见
    }
}

数据 Data.java

import javax.swing.*;
import java.net.URL;

//数据中心
public class Data {

    //相对路径 tx.jpg
    //绝对路径  /相当于当前的项目
    public static URL headerURL = Data.class.getResource("statics/header.png");
    public static ImageIcon header = new ImageIcon(headerURL);
    public static URL upURL = Data.class.getResource("statics/up.png");
    public static ImageIcon up = new ImageIcon(upURL);
    public static URL downURL = Data.class.getResource("statics/down.png");
    public static ImageIcon down = new ImageIcon(downURL);
    public static URL leftURL = Data.class.getResource("statics/left.png");
    public static ImageIcon left = new ImageIcon(leftURL);
    public static URL rightURL = Data.class.getResource("statics/right.png");
    public static ImageIcon right = new ImageIcon(rightURL);
    public static URL bodyURL = Data.class.getResource("statics/body.png");
    public static ImageIcon body = new ImageIcon(bodyURL);
    public static URL foodURL = Data.class.getResource("statics/food.png");
    public static ImageIcon food = new ImageIcon(foodURL);
}

游戏面板 Panel.java

import javax.crypto.KeyGenerator;
import javax.swing.*;
import java.awt.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.security.Key;
import java.util.Random;

//游戏的面板
public class Panel extends JPanel implements KeyListener, ActionListener {

    int length;//定义蛇的长度

    int[] snakex = new int[600];//蛇的x坐标 25*25
    int[] snakey = new int[500];//蛇的y坐标 25*25
    String direction = "R";//初始方向向右
    boolean Start = false;//游戏状态默认不开始
    boolean Fail = false;//游戏失败状态
    //食物的坐标
    int foodx;
    int foody;
    //用来防止食物出现在身体里
    int a;
    int b;
    int c=0;//c==0指食物没有与身体重合
    //积分
    int score;
    Random random = new Random();


    //定时器，以毫秒为单位
    Timer timer = new Timer(100,this);//100毫秒执行一次
    //构造器
    public Panel(){
        inti();
        //获得焦点和键盘事件
        this.setFocusable(true);//获得焦点事件，组件失去焦点就会发生焦点事件
        this.addKeyListener(this);//获得键盘监听事件
        timer.start();//游戏一开始定时器启动
    }

    //初始化方法
    public void inti(){
        length = 3;
        score = 0;
        snakex[0] = 100;snakey[0] = 100;//脑袋
        snakex[1] = 75;snakey[1] = 100;//第一个身体
        snakex[2] = 50;snakey[2] = 100;//第二个身体

        //把食物随机出现在窗口上
        foodx = 25+25*random.nextInt(34);
        foody = 75+25*random.nextInt(24);


    }

    //绘制面板，我们游戏中的所有东西，都是用这个画笔来画
    @Override
    protected void paintComponent(Graphics g) {
        super.paintComponent(g);//清屏
        //绘制静态的面板
        this.setBackground(Color.BLACK);//背景颜色
        Data.header.paintIcon(this,g,25,11);//头部广告栏
        g.fillRect(25,75,850,600);//默认的游戏界面
        //画积分
        g.setColor(Color.BLUE);
        g.setFont(new Font("宋体",Font.BOLD,18));
        g.drawString("长度"+length,750,35);
        g.drawString("分数"+score,750,55);
        //画食物
        Data.food.paintIcon(this,g,foodx,foody);

        //把小蛇画上去 用switch无法正常显示头部方向，不知道为什么。
//        switch (direction)
//        {
//            case "R":
//                Data.right.paintIcon(this,g,snakex[0],snakey[0]);//蛇头初始化向右，需要通过方向来判断
//            case "L":
//                Data.left.paintIcon(this,g,snakex[0],snakey[0]);
//            case "U":
//                Data.up.paintIcon(this,g,snakex[0],snakey[0]);
//            case "D":
//                Data.down.paintIcon(this,g,snakex[0],snakey[0]);
//        }

        //把小蛇画上去
        if (direction.equals("R")){ //蛇的头通过方向变量来判断
            Data.right.paintIcon(this,g,snakex[0],snakey[0]);
        }else if (direction.equals("L")){
            Data.left.paintIcon(this,g,snakex[0],snakey[0]);
        }else if (direction.equals("U")){
            Data.up.paintIcon(this,g,snakex[0],snakey[0]);
        }else if (direction.equals("D")){
            Data.down.paintIcon(this,g,snakex[0],snakey[0]);
        }

        for (int i = 1; i < length; i++) //身体坐标
        {
            Data.body.paintIcon(this,g,snakex[i],snakey[i]);
        }


        //游戏状态
        if (!Start){
            g.setColor(Color.WHITE);
            g.setFont(new Font("微软黑体",Font.BOLD,40));//设置字体
            g.drawString("按下空格开始游戏",300,300);//写字
        }

        if(Fail){
            g.setColor(Color.RED);
            g.setFont(new Font("微软黑体",Font.BOLD,40));//设置字体
            g.drawString("游戏失败，按下空格重新开始",300,300);//写字
        }
    }


    //键盘监听事件
    @Override
    public void keyPressed(KeyEvent e) {
        int keyCode = e.getKeyCode();//获得键盘按键是哪个
        if (keyCode == KeyEvent.VK_SPACE){
            if (Fail){
                //重新开始
                Fail = false;
                inti();
            }
            else{
                Start = !Start;
            }
            repaint();
        }
        //小蛇移动
        if (keyCode == KeyEvent.VK_UP && direction!="D"){
            direction = "U";
        }
        else if(keyCode == KeyEvent.VK_DOWN && direction!="U"){
            direction = "D";
        }
        else if (keyCode == KeyEvent.VK_LEFT && direction!="R"){
            direction = "L";
        }
        else if (keyCode == KeyEvent.VK_RIGHT && direction!="L"){
            direction = "R";
        }
    }

    //事件监听，需要通过固定事件来刷新，1S=10次;
    @Override
    public void actionPerformed(ActionEvent e) {
        if (Start && !Fail){//如果游戏是开始状态，就让小蛇动起来
            //吃食物
            if (snakex[0] == foodx&& snakey[0] == foody){
                length++;
                score++;
                Boolean A=true;
                //再次随机初始化食物
                //这里是防止食物出现的位置与身体重合
                while (A) {
                    a = 25 + 25 * random.nextInt(34);
                    b = 75 + 25 * random.nextInt(24);
                    for (int i = 0; i < length; i++) {
                        if (a != snakex[i] && b != snakey[i]) {
                            c = 0;
                        } else if (a == snakex[i] && b == snakey[i]) {
                            c = 1;
                            break;
                        }
                    }
                    if (c == 0) {
                        break;
                    }
                }
                foodx = 25 + 25 * random.nextInt(34);
                foody = 75 + 25 * random.nextInt(24);
            }

            //移动
            for (int i = length-1; i >0 ; i--) {//身子后一节移到前一节的位置
                snakex[i] = snakex[i-1];
                snakey[i] = snakey[i-1];
            }
            //身体走向,边界判断
            if (direction.equals("R")){
                snakex[0] = snakex[0]+25;
                if (snakex[0]>850){
                    snakex[0] =25;
                }
            }
            else if (direction.equals("U")){
                snakey[0] = snakey[0]-25;
                if (snakey[0]<75){
                    snakey[0] =650;
                }
            }
            else if (direction.equals("L")){
                snakex[0] = snakex[0]-25;
                if (snakex[0]<25){
                    snakex[0] =850;
                }
            }
            else if (direction.equals("D")){
                snakey[0] = snakey[0]+25;
                if (snakey[0]>650){
                    snakey[0] =75;
                }
            }
            //撞到自己就算失败
            for (int i = 1; i < length; i++) {
                if(snakex[0] == snakex[i] && snakey[0] == snakey[i])
                {
                    Fail = true;
                }
            }
            repaint();
        }
        timer.start();//定时器开始
    }

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