视频链接：21、贪吃蛇之界面绘制_哔哩哔哩_bilibili
https://www.bilibili.com/video/BV1DJ411B75F?p=21&vd_source=b5775c3a4ea16a5306db9c7c1c1486b5
1.游戏中用的的图片素材
1.贪吃蛇游戏的主启动类StartGame；
package com.yundait.snake;import javax.swing.*;
import java.awt.*;//贪吃蛇游戏的主启动类；
public class StartGame {public static void main(String[] args) {JFrame frame = new JFrame("我的游戏—贪吃蛇");//创建游戏窗口frame.setBounds(10,10,915,745);//设置窗口的位置和长宽frame.setResizable(false);//设置窗口尺寸不可调frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);//设置窗口关闭事件Container container = frame.getContentPane();//创建一个内容窗格的容器container.add(new GamePanel());//将面板放在容器上frame.setVisible(true);//设置窗口可见}
}
2.贪吃蛇游戏的数据类Data：存放游戏界的图片
package com.yundait.snake;import javax.swing.*;
import java.net.URL;
public class Data {public static URL headerURL = Data.class.getResource("statics/header.png");//获取标题图片public static ImageIcon header = new ImageIcon(headerURL);//创建标题图标public static URL upURL = Data.class.getResource("statics/up.png");//获取朝上的头部图片public static URL downURL = Data.class.getResource("statics/down.png");//获取朝下的头部图片public static URL leftURL = Data.class.getResource("statics/left.png");//获取朝左的头部图片public static URL rightURL = Data.class.getResource("statics/right.png");//获取朝右的头部图片public static URL bodyURL = Data.class.getResource("statics/body.png");//获取朝右的头部图片public static ImageIcon up = new ImageIcon(upURL);//创建朝上的头部图标public static ImageIcon down = new ImageIcon(downURL);//创建朝下的头部图标public static ImageIcon left = new ImageIcon(leftURL);//创建朝左的头部图标public static ImageIcon right = new ImageIcon(rightURL);//创建朝右的头部图标public static ImageIcon body = new ImageIcon(bodyURL);//创建朝右的头部图标public static URL foodURL = Data.class.getResource("statics/food.png");//获取食物图片public static ImageIcon food = new ImageIcon(foodURL);//创建食物图标
}
3.贪吃蛇游戏的游戏面板GamePanel：主要功能都在类下此实现
package com.yundait.snake;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.util.Random;//游戏的面板
public class GamePanel extends JPanel implements KeyListener, ActionListener {int length; //定义蛇的长度int[]snakeX= new int[600];//蛇的X坐标int[]snakeY= new int[500];//蛇的Y坐标String direction;//定义小蛇头的方向参数int food_x;int food_y;int score;Random random = new Random();boolean isStart;//游戏开始、结束的状态boolean isFail;//游戏失败状态Timer timer = new Timer(100,this);//创建一个定时器，每100毫秒执行一次（每秒执行10次）//构造器方法public GamePanel() {init();this.setFocusable(true);//获得焦点事件this.addKeyListener(this);//添加键盘监听}//数据初始化方法public void init(){length = 3;//初始化小蛇长度，包含小蛇头snakeX[0] = 100;snakeY[0] = 100;//初始化小蛇脑袋的坐标snakeX[1] = 75;snakeY[1] = 100;//初始化小蛇第1段身体的坐标snakeX[2] = 50 ;snakeY[2] = 100;//初始化小蛇第2段身体的坐标direction = "right"; //初始化小蛇头的方向（向右）isStart = false;//游戏默认处于停止状态isFail = false;timer.start();//游戏一开始，就启动定时器。score = 0;//把食物随机分派在界面上food_x = 25 + 25*random.nextInt(34);food_y = 75 + 25*random.nextInt(24);}//绘制面板，我们游戏中的所有东西，都用这支画笔来画@Overrideprotected void paintComponent(Graphics g) {//清屏super.paintComponent(g);//绘制静态游戏面板this.setBackground(new Color(255, 255, 255));//设置面板的颜色Data.header.paintIcon(this,g,25,11);//把头部广告栏画上去g.setColor(new Color(110, 164, 176));//设置画笔的颜色g.fillRect(25,75,850,600);//画一个默认的矩形游戏界面//把分数画在界面上g.setColor(Color.white);g.setFont(new Font("微软雅黑",Font.BOLD,18));g.drawString("长度:" + length,750,30);g.drawString("分数:" + score,750,55);//把食物画在界面上Data.food.paintIcon(this,g,food_x,food_y);//使用switch选择结构把小蛇的头画在面板上switch (direction){case "right":Data.right.paintIcon(this,g,snakeX[0],snakeY[0]);//把朝右的小蛇头画在面板上break;case "left":Data.left.paintIcon(this,g,snakeX[0],snakeY[0]);//把朝左的小蛇头画在面板上break;case "up":Data.up.paintIcon(this,g,snakeX[0],snakeY[0]);//把朝上的小蛇头画在面板上break;case "down":Data.down.paintIcon(this,g,snakeX[0],snakeY[0]);//把朝下的小蛇头画在面板上break;}//使用循环结构把小蛇身体画在面板上for (int i = 1; i < length; i++) {Data.body.paintIcon(this,g,snakeX[i],snakeY[i]);}//判断游戏状态，按下空格键开始或结束游戏if (!isStart){g.setColor(Color.white);g.setFont(new Font("微软雅黑",Font.BOLD,40));g.drawString("请按下空格开始游戏",300,350);}//判断游戏是否失败，失败后显示："游戏失败，按下空格重新开始"if (isFail){g.setColor(Color.red);g.setFont(new Font("微软雅黑",Font.BOLD,40));g.drawString("游戏失败，按下空格重新开始",300,350);}}//键盘监听事件@Overridepublic void keyPressed(KeyEvent e) {int keyCode = e.getKeyCode();//获得键盘按下了哪一个if (keyCode == KeyEvent.VK_SPACE){if (isFail){//游戏重新开始isFail =false;init();}else {isStart = !isStart;//游戏状态取反}repaint();}//监听键盘输入，根据键盘输入不同，改变小蛇方向if (keyCode == KeyEvent.VK_UP && !direction.equals("down")){direction = "up";} else if (keyCode == KeyEvent.VK_DOWN && !direction.equals("up")) {direction = "down";} else if (keyCode == KeyEvent.VK_LEFT && !direction.equals("right")) {direction = "left";} else if (keyCode == KeyEvent.VK_RIGHT && !direction.equals("left")) {direction = "right";}}//事件监听----需要通过固定的时间来刷新@Overridepublic void actionPerformed(ActionEvent e) {if (isStart && !isFail){//监听小蛇吃食物if (snakeX[0] == food_x && snakeY[0] == food_y){//再次随机一个食物的坐标food_x = 25 + 25*random.nextInt(34);food_y = 75 + 25*random.nextInt(24);//吃完食物，身体长度加1length = length +1;score+=10;}//使用for循环让小蛇的后一节身体一动到前一节位置for (int i = length-1; i > 0 ; i--) {snakeX[i] = snakeX[i-1];snakeY[i] = snakeY[i-1];}//控制小蛇移动，撞墙后游戏失败if (direction.equals("right")){snakeX[0] = snakeX[0]+25;if (snakeX[0]>850){isFail = true;}} else if (direction.equals("left")) {snakeX[0] = snakeX[0]-25;if (snakeX[0]<25){isFail = true;}} else if (direction.equals("up")) {snakeY[0] = snakeY[0]-25;if (snakeY[0]<75){isFail = true;}} else if (direction.equals("down")) {snakeY[0] = snakeY[0]+25;if (snakeY[0]>650){isFail = true;}}//判断小蛇是否撞到自己，撞到自己后游戏失败for (int i = 1; i < length; i++) {if (snakeX[0]==snakeX[i] && snakeY[0] == snakeY[i]){isFail = true;break;}}repaint();//刷新}timer.start();//启动计时器}@Overridepublic void keyTyped(KeyEvent e) {}//用不到，不需要重写方法，放在这里即可；@Overridepublic void keyReleased(KeyEvent e) {}//用不到，不需要重写方法，放在这里即可；
}
4.GUI编程内容总结
