【GUI】-- 14 GUI编程总结

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*25
    int[] snakeY = new int[500];  //蛇的Y坐标 25*25
    String 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
    @Override
    protected 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
    @Override
    public 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)
    @Override
    public 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();
    }
    @Override
    public void keyReleased(KeyEvent e) {}
    @Override
    public 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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