GUI编程

05 GUI总结

在总结之前，先给出之前的贪吃蛇小游戏全代码。

• 游戏的主启动类：

package com.duo.snake;import javax.swing.*;//游戏的主启动类
public class StartGame {public static void main(String[] args) {JFrame frame = new JFrame();frame.add(new GamePanel());  //此行代码的位置会影响后续按下空格时游戏的反应(Tab键问题)！！！frame.setVisible(true);frame.setResizable(false);frame.setTitle("贪吃蛇-2023");frame.setBounds(5, 10, 915, 740);frame.setLocationRelativeTo(null);frame.setDefaultCloseOperation(WindowConstants.EXIT_ON_CLOSE);}
}

• GamePanel类：

package com.duo.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 {//定义蛇的数据结构int length;  //小蛇总长int[] snakeX = new int[600];  //蛇的X坐标 25*25int[] snakeY = new int[500];  //蛇的Y坐标 25*25String direction;  //蛇头方向boolean isStart = false;  //默认未开始游戏boolean isFail = false;  //游戏失败状态Timer timer = new Timer(100, this);  //定时器，100ms执行一次//食物的坐标int foodX;int foodY;Random random = new Random();//积分面板数据结构int score;//构造器public GamePanel() {init();this.setFocusable(true);  //获取焦点事件this.addKeyListener(this);  //获取键盘监听事件timer.start();  //游戏一开始，定时器就启动}//初始化方法public void init() {length = 3;snakeX[0] = 100; snakeY[0] = 100;  //脑袋的坐标snakeX[1] = 75; snakeY[1] = 100;  //第一节身体的坐标snakeX[2] = 50; snakeY[2] = 100;  //第二节身体的坐标direction = "R";  //蛇头初始向右//将食物随机分布于游戏界面foodX = 25 + 25 * random.nextInt(34);foodY = 75 + 25 * random.nextInt(24);score = 0;  //定义初始得分}//绘制静态面板@Overrideprotected void paintComponent(Graphics g) {super.paintComponent(g);  //起到清屏的作用Data.header.paintIcon(this, g, 25, 11);  //将广告栏画入面板g.fillRect(25, 75, 850, 600);  //默认的游戏界面(黑色区域)this.setBackground(Color.white);//画出积分面板g.setColor(Color.white);g.setFont(new Font("宋体", Font.BOLD, 18));g.drawString("长度  " + length, 750, 30);g.drawString("得分  " + score, 750, 55);//画出食物Data.food.paintIcon(this, g, foodX, foodY);//将小蛇(头)画入面板中的游戏区域，且蛇头部分需要判断方向switch (direction) {case "R":Data.right.paintIcon(this, g, snakeX[0], snakeY[0]);break;case "L":Data.left.paintIcon(this, g, snakeX[0], snakeY[0]);break;case "U":Data.up.paintIcon(this, g, snakeX[0], snakeY[0]);break;case "D":Data.down.paintIcon(this, g, snakeX[0], snakeY[0]);break;}//画小蛇的其余身体部分for (int i = 1; i < length; i++) {Data.body.paintIcon(this, g, snakeX[i], snakeY[i]);}//绘制当前游戏状态if (!isStart) {g.setColor(Color.white);g.setFont(new Font("宋体", Font.BOLD, 40));g.drawString("按下空格开始游戏", 270, 300);}if (isFail) {g.setColor(Color.red);g.setFont(new Font("宋体", Font.BOLD, 40));g.drawString("游戏失败，按下空格重新开始", 220, 300);}}//键盘监听事件@Overridepublic void keyPressed(KeyEvent e) {int keyCode = e.getKeyCode();  //获取键盘按键if (keyCode == KeyEvent.VK_SPACE) {if (isFail) {  //重新开始isFail = false;init();} else {  //正常开始isStart = !isStart;repaint();}}//键盘监听到按键后画上对应方向的蛇头if (keyCode == KeyEvent.VK_UP && !direction.equals("D")) {direction = "U";} else if (keyCode == KeyEvent.VK_DOWN && !direction.equals("U")) {direction = "D";} else if (keyCode == KeyEvent.VK_LEFT && !direction.equals("R")) {direction = "L";} else if (keyCode == KeyEvent.VK_RIGHT && !direction.equals("L")) {direction = "R";}}//事件监听需要定时器来实现，即通过固定的时间进行刷新(例如1s=10次)@Overridepublic void actionPerformed(ActionEvent e) {if (isStart && !isFail) {//小蛇身体右移for (int i = length - 1; i > 0; i--) {  //后一节身体移动至前一节 snakeX[1] = snakeX[0]snakeX[i] = snakeX[i - 1];snakeY[i] = snakeY[i - 1];}//判断蛇头是否吃到食物if (snakeX[0] == foodX && snakeY[0] == foodY) {length++;foodX = 25 + 25 * random.nextInt(34);foodY = 75 + 25 * random.nextInt(24);score += 10;}//判断蛇头走向switch (direction) {case "R":snakeX[0] += 25;//边界判断if (snakeX[0] > 850) {snakeX[0] = 25;}break;case "L":snakeX[0] -= 25;//边界判断if (snakeX[0] < 25) {snakeX[0] = 850;}break;case "U":snakeY[0] -= 25;//边界判断if (snakeY[0] < 75) {snakeY[0] = 650;}break;case "D":snakeY[0] += 25;//边界判断if (snakeY[0] > 650) {snakeY[0] = 75;}break;}//游戏失败判定for (int i = 1; i < length; i++) {if (snakeX[0] == snakeX[i] && snakeY[0] == snakeY[i]) {isFail = true;break;}}repaint();}timer.start();}@Overridepublic void keyReleased(KeyEvent e) {}@Overridepublic void keyTyped(KeyEvent e) {}
}

游戏的数据中心类：

package com.duo.snake;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("static/header.png");public static URL upURL = Data.class.getResource("static/up.png");public static URL downURL = Data.class.getResource("static/down.png");public static URL leftURL = Data.class.getResource("static/left.png");public static URL rightURL = Data.class.getResource("static/right.png");public static URL bodyURL = Data.class.getResource("static/body.png");public static URL foodURL = Data.class.getResource("static/food.png");public static ImageIcon header = new ImageIcon(headerURL);public static ImageIcon up = new ImageIcon(upURL);public static ImageIcon down = new ImageIcon(downURL);public static ImageIcon left = new ImageIcon(leftURL);public static ImageIcon right = new ImageIcon(rightURL);public static ImageIcon body = new ImageIcon(bodyURL);public static ImageIcon food = new ImageIcon(foodURL);}

游戏运行结果已于前节展示，可实现小蛇移动、吃到食物长大并且分数增加、失败判定等操作。下面将对此阶段GUI编程作一简单总结。

GUI编程：

• AWT
  1. 组件
  2. 容器
  3. 面板
  4. 事件监听
  5. 文本框监听
  6. 画图类paint(g)
  7. 鼠标/窗口/键盘监听器
• Swing
  1. 容器
  2. 面板(可带有滚动条)
  3. label
     • 普通标签
     • 图片标签
     • 图像标签
  4. 按钮
     • 普通按钮
     • 图片按钮
     • 单选框按钮
     • 多选框按钮
  5. 列表
     • 下拉框
     • 列表框
  6. 文本框
     • 普通文本框
     • 密码框
     • 文本域
• 贪吃蛇小游戏

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