Java实现经典游戏之大鱼吃小鱼

2022-10-07,,

一、项目演示

点击观看项目演示视频

二、项目实现

1.创建游戏窗口

创建一个游戏窗口类 gamewin,创建一个 launch() 启动方法,在其中设置窗口相关属性:

import javax.swing.*;

public class gamewin extends jframe {
    int width = 1440;
    int height = 900;

    //创建一个启动方法,设置窗口信息
    public void launch() {
        this.setvisible(true);                          //设置窗口可见
        this.setsize(width, height);                    //设置窗口大小
        this.setlocationrelativeto(null);               //设置窗口居中
        this.setresizable(false);                       //设置窗口大小不可改变
        this.settitle("大鱼吃小鱼");                     //设置窗口标题
        this.setdefaultcloseoperation(exit_on_close);   //设置窗口按钮
    }
}

创建一个游戏窗口测试类 gamewindemo,进行窗口对象的创建和启动方法的调用:

public class gamewindemo {
    public static void main(string[] args) {
        //创建一个游戏窗口对象
        gamewin gamewin = new gamewin();

        //启动窗口
        gamewin.launch();
    }
}

2.添加背景图片

将下载的背景图片的文件夹复制到项目文件夹中:

创建一个工具类 gameutils,在其中添加背景图片:

import java.awt.*;

public class gameutils {
    public static image bgimg = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\sea.jpg");
}

在 gamewin 类中添加 paint 方法,在其中绘制背景图片:

@override
public void paint(graphics g) {
    //用画笔绘制背景图片
    g.drawimage(gameutils.bgimg, 0, 0, null);
}

如果发现背景图片加载不出来,先检查一下路径有没有写错,相对路径不行的话就试试绝对路径;有时候加载背景图片会较慢,可以试着将运行出来的窗口最小化后再恢复

3.制作封面

定义默认游戏状态,同时在 paint 方法中对游戏状态进行判断进而显示对应的游戏界面:

import javax.swing.*;
import java.awt.*;

public class gamewin extends jframe {
    int width = 1440;
    int height = 900;

    //定义游戏默认状态
    static int state = 0;

    //创建一个启动方法,设置窗口信息
    public void launch() {
        this.setvisible(true);                          //设置窗口可见
        this.setsize(width, height);                    //设置窗口大小
        this.setlocationrelativeto(null);               //设置窗口居中
        this.setresizable(false);                       //设置窗口大小不可改变
        this.settitle("大鱼吃小鱼");                     //设置窗口标题
        this.setdefaultcloseoperation(exit_on_close);   //设置窗口按钮
    }

    @override
    public void paint(graphics g) {
        //用画笔绘制背景图片
        g.drawimage(gameutils.bgimg, 0, 0, null);

		//游戏状态:0未开始,1游戏中,2游戏失败,3游戏胜利,4游戏暂停,5重新开始
        switch (state) {
            case 0:
                g.drawimage(gameutils.bgimg, 0, 0, null);
                //为启动页面添加文字
                g.setcolor(color.pink);
                g.setfont(new font("仿宋", font.bold, 60));
                g.drawstring("请点击开始游戏", 600, 500);
                break;
            case 1:
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }
    }
}

4.启动页面的点击事件

在启动方法中添加鼠标监听器,当点击启动页面时游戏开始

//创建一个启动方法,设置窗口信息
public void launch() {
    this.setvisible(true);                          //设置窗口可见
    this.setsize(width, height);                    //设置窗口大小
    this.setlocationrelativeto(null);               //设置窗口居中
    this.setresizable(false);                       //设置窗口大小不可改变
    this.settitle("大鱼吃小鱼");                     //设置窗口标题
    this.setdefaultcloseoperation(exit_on_close);   //设置窗口按钮

    //添加鼠标监听事件
    this.addmouselistener(new mouseadapter() {
        @override
        public void mouseclicked(mouseevent e) {
            if (e.getbutton() == 1 && state == 0) {
                state = 1;
                repaint();
            }
        }
    });
}

5.游戏开始时的背景添加

新建一个背景图的实体类 bg,在 gamewin 类里创建其对象,并在 case 1 中调用绘制背景图的方法

import java.awt.*;

public class bg {
    void paintself(graphics g) {
        g.drawimage(gameutils.bgimg, 0, 0, null);
    }
}

由于游戏中需要不断绘制背景图片,所以我们在启动方法中添加一个 while 循环,在其中每隔 40 毫秒重绘背景图

import javax.swing.*;
import java.awt.*;
import java.awt.event.*;

public class gamewin extends jframe {
    int width = 1440;
    int height = 900;

    //定义游戏默认状态
    static int state = 0;

    //获取背景图类的对象
    bg bg = new bg();

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        this.setvisible(true);                          //设置窗口可见
        this.setsize(width, height);                    //设置窗口大小
        this.setlocationrelativeto(null);               //设置窗口居中
        this.setresizable(false);                       //设置窗口大小不可改变
        this.settitle("大鱼吃小鱼");                     //设置窗口标题
        this.setdefaultcloseoperation(exit_on_close);   //设置窗口按钮

        //添加鼠标监听事件
        this.addmouselistener(new mouseadapter() {
            @override
            public void mouseclicked(mouseevent e) {
                if (e.getbutton() == 1 && state == 0) {
                    state = 1;
                    repaint();
                }
            }
        });

        //背景图片重复使用,需要重复调用repaint方法
        while(true) {
            repaint();
            thread.sleep(40);
        }
    }

    @override
    public void paint(graphics g) {
        //用画笔绘制背景图片
        g.drawimage(gameutils.bgimg, 0, 0, null);

        switch (state) {
            case 0:
                g.drawimage(gameutils.bgimg, 0, 0, null);
                //为启动页面添加文字
                g.setcolor(color.pink);
                g.setfont(new font("仿宋", font.bold, 60));
                g.drawstring("请点击开始游戏", 500, 500);
                break;
            case 1:
                bg.paintself(g);
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }
    }
}

6.双缓存解决闪屏问题

如果此时你的屏幕出现闪烁的情况,可以用下面的方法解决

整体思路为:

重新创建一个空的图片,将所有的组件先绘制到空的图片上,然后把绘制好的图片一次性地绘制到主窗口上

创建一个空图片对象,在 paint 方法中将所有组件绘制到空图片上,再一次性绘制到主窗口上

public class gamewin extends jframe {
    int width = 1440;
    int height = 900;

    //定义游戏默认状态
    static int state = 0;

    //获取背景图类的对象
    bg bg = new bg();

    //创建一个空图片对象
    image offscreenimage;

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        this.setvisible(true);                          //设置窗口可见
        this.setsize(width, height);                    //设置窗口大小
        this.setlocationrelativeto(null);               //设置窗口居中
        this.setresizable(false);                       //设置窗口大小不可改变
        this.settitle("大鱼吃小鱼");                     //设置窗口标题
        this.setdefaultcloseoperation(exit_on_close);   //设置窗口按钮

        //添加鼠标监听事件
        this.addmouselistener(new mouseadapter() {
            @override
            public void mouseclicked(mouseevent e) {
                if (e.getbutton() == 1 && state == 0) {
                    state = 1;
                    repaint();
                }
            }
        });

        //背景图片重复使用,需要重复调用repaint方法
        while (true) {
            repaint();
            thread.sleep(40);
        }
    }

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //把组件重新绘制到主窗口中
                gimage.drawimage(gameutils.bgimg, 0, 0, null);
                //为启动页面添加文字
                gimage.setcolor(color.pink);
                gimage.setfont(new font("仿宋", font.bold, 60));
                gimage.drawstring("请点击开始游戏", 500, 500);
                break;
            case 1:
                bg.paintself(gimage);
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }
}

7.敌方第一条小雨的添加

新建敌方鱼的父类 enamy,编写左敌方鱼类 enamy_1_l 继承父类

import java.awt.*;

public class enamy {
    //定义图片
    image img;

    //定义物体坐标
    int x;
    int y;
    int width;
    int height;

    //移动速度
    int speed;

    //方向
    int dir = 1;

    //敌方鱼的类型、分值
    int type;
    int count;

    //绘制自身方法
    public void paintself(graphics g) {
        g.drawimage(img, x, y, width, height, null);
    }

    //获取自身矩形用于碰撞检测
    public rectangle getrec() {
        return new rectangle(x, y, width, height);
    }
}

//左敌方鱼类
class enamy_1_l extends enamy {
    enamy_1_l() {
        this.x = -45;
        this.y = (int) (math.random() * 700 + 100);
        this.width = 45;
        this.height = 69;
        this.speed = 10;
        this.count = 1;
        this.img = gameutils.enamy_l_img;
    }
}

在 gameutils 类中添加左敌方鱼类的图片

public class gameutils {
    //背景图
    public static image bgimg = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\sea.jpg");

    //敌方鱼类
    public static image enamy_l_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish1_r.gif");
}

在 gamewin 类中创建左敌方鱼类对象并在 case 1 的情况下绘制左敌方鱼类

public class gamewin extends jframe {
    //......

    //敌方鱼类
    enamy enamy = new enamy_1_l();

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        //......
    }

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //把组件重新绘制到主窗口中
                gimage.drawimage(gameutils.bgimg, 0, 0, null);
                //为启动页面添加文字
                gimage.setcolor(color.pink);
                gimage.setfont(new font("仿宋", font.bold, 60));
                gimage.drawstring("请点击开始游戏", 500, 500);
                break;
            case 1:
                bg.paintself(gimage);
                enamy.paintself(gimage);
                enamy.x += enamy.speed;
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }
}

8.敌方左方小鱼的批量添加

在工具类中创建一个所有敌方鱼物体的集合

public class gameutils {
    //敌方鱼类集合
    public static list<enamy> enamylist = new arraylist<>();
    
    //......
}

在窗口类中添加一个方法,用于批量添加敌方鱼类

public class gamewin extends jframe {
    //......

    //敌方鱼类
    enamy enamy;

    //计数器,用来记录游戏的重绘次数,也是鱼生成的数量
    int time = 0;

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        //......
        });

        //背景图片重复使用,需要重复调用repaint方法
        while (true) {
            repaint();
            time++;
            thread.sleep(40);
        }
    }

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //......
            case 1:
                bg.paintself(gimage);
                logic();        //不断添加敌方鱼类
                //遍历敌方鱼类集合,绘制敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    void logic() {
        //每重绘10次生成一条敌方鱼类
        if (time % 10 == 0) {
            enamy = new enamy_1_l();
            gameutils.enamylist.add(enamy);
        }

        //移动方向
        for (enamy enamy : gameutils.enamylist) {
            enamy.x = enamy.x + enamy.dir * enamy.speed;
        }
    }
}

9.我方鱼的生成

在工具类中添加我方鱼类的图片

public class gameutils {
    //......
    
    //我方鱼类
    public static image myfishimg_l = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\myfish\\myfish_left.gif");
    public static image myfishimg_r = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\myfish\\myfish_right.gif");
}

创建我方鱼类

import java.awt.*;

public class myfish {
    //图片
    image img = gameutils.myfishimg_l;
    //坐标
    int x = 700;
    int y = 500;
    int width = 50;
    int height = 50;
    //移动速度
    int speed = 20;
    //等级
    int level = 1;

    //绘制自身的方法
    public void paintself(graphics g) {
        g.drawimage(img, x, y, width, height, null);
    }

    //获取自身矩形的方法
    public rectangle getrec() {
        return new rectangle(x, y, width, height);
    }
}

在窗口类中获取我方鱼的对象

//我方鱼类
myfish myfish = new myfish();

在工具类中添加方向判定,用来控制我方鱼的方向

public class gameutils {
    //方向
    static boolean up = false;
    static boolean down = false;
    static boolean left = false;
    static boolean right = false;

    //......
}

在我方鱼类添加一个方法,实现对键盘的控制

public class myfish {
    //......

    //绘制自身的方法
    public void paintself(graphics g) {
    	//调用方法
        logic();
        g.drawimage(img, x, y, width, height, null);
    }

    //......

    void logic() {
        if (gameutils.up) {
            y = y - speed;
        }
        if (gameutils.down) {
            y = y + speed;
        }

        if (gameutils.left) {
            x = x - speed;
            img = gameutils.myfishimg_l;
        }
        if (gameutils.right) {
            x = x + speed;
            img = gameutils.myfishimg_r;
        }
    }
}

在窗口类的 paint 方法的 case 1 中,添加我方鱼类所创造的方法

import javax.swing.*;
import java.awt.*;
import java.awt.event.keyadapter;
import java.awt.event.keyevent;
import java.awt.event.mouseadapter;
import java.awt.event.mouseevent;

public class gamewin extends jframe {
    //......

    //我方鱼类
    myfish myfish = new myfish();

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        //......
        });

        //键盘移动
        this.addkeylistener(new keyadapter() {
            @override//按压
            public void keypressed(keyevent e) {
                //上下左右四个键的ascii值为 上 ↑:38下 ↓: 40左 ←: 37右 →: 39
                if (e.getkeycode() == 38) {
                    gameutils.up = true;
                }
                if (e.getkeycode() == 40) {
                    gameutils.down = true;
                }
                if (e.getkeycode() == 37) {
                    gameutils.left = true;
                }
                if (e.getkeycode() == 39) {
                    gameutils.right = true;
                }
            }

            @override//抬起
            public void keyreleased(keyevent e) {
                if (e.getkeycode() == 38) {
                    gameutils.up = false;
                }
                if (e.getkeycode() == 40) {
                    gameutils.down = false;
                }
                if (e.getkeycode() == 37) {
                    gameutils.left = false;
                }
                if (e.getkeycode() == 39) {
                    gameutils.right = false;
                }
            }
        });

        //......
    }

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //......
                break;
            case 1:
                bg.paintself(gimage);
                myfish.paintself(gimage);
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    void logic() {
        //......
    }
}

10.我方鱼与敌方小鱼的碰撞测试

在游戏中所有物体被视为矩形,两个物体是否碰撞,即检测两个物体的所在矩形是否有重叠部分

具体检测,就是让我方鱼与敌方鱼的矩形进行一一检测,在窗口类的 logic() 方法中实现

//批量添加鱼类
void logic() {
    //每重绘10次生成一条敌方鱼类
    if (time % 10 == 0) {
        enamy = new enamy_1_l();
        gameutils.enamylist.add(enamy);
    }

    //移动方向
    for (enamy enamy : gameutils.enamylist) {
        enamy.x = enamy.x + enamy.dir * enamy.speed;

        //我方鱼与敌方鱼的碰撞检测
        if (myfish.getrec().intersects(enamy.getrec())) {
            enamy.x = -200;
            enamy.y = -200;
        }
    }
}

11.游戏积分的实现

在工具类中定义分数

//分数
static int count = 0;

在窗口类中实现我方鱼吃掉敌方鱼增加分数,同时在页面上打印分数

public class gamewin extends jframe {
    //......

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //......
            case 1:
                bg.paintself(gimage);
                //*******打印所得积分********
                gimage.setcolor(color.orange);
                gimage.setfont(new font("仿宋", font.bold, 50));
                gimage.drawstring("积分:" + gameutils.count, 200, 120);
                myfish.paintself(gimage);
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                break;
            case 2:
                break;
            case 3:
                break;
            case 4:
                break;
            default:
                break;
        }

        //......

    //批量添加鱼类
    void logic() {
        //......

        //移动方向
        for (enamy enamy : gameutils.enamylist) {
            enamy.x = enamy.x + enamy.dir * enamy.speed;

            //我方鱼与敌方鱼的碰撞检测
            if (myfish.getrec().intersects(enamy.getrec())) {
                enamy.x = -200;
                enamy.y = -200;
                //********得分********
                gameutils.count += enamy.count;
            }
        }
    }
}

在我方鱼类中实现吃掉敌方鱼后,我方鱼体积增加

public class myfish {
    //......

    //绘制自身的方法
    public void paintself(graphics g) {
        logic();
        g.drawimage(img, x, y, width + gameutils.count, height + gameutils.count, null);
    }

    //获取自身矩形的方法
    public rectangle getrec() {
        return new rectangle(x, y, width + gameutils.count, height + gameutils.count);
    }

   //......
}

12.关卡的设置

根据积分来实现关卡的设置,如果达到目标积分则过关,并增加我方鱼的等级

在工具类中定义关卡等级

//关卡等级
static int level = 0;

在窗口类的 logic() 方法中设置关卡

public class gamewin extends jframe {
    //......

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象

        switch (state) {
            case 0:
                //......
                break;
            case 1:
                //......
                break;
            case 2:
                break;
            case 3: //玩家胜利
            	bg.paintself(gimage);
                myfish.paintself(gimage);
                gimage.setcolor(color.orange);
                gimage.setfont(new font("仿宋", font.bold, 80));
                gimage.drawstring("积分: " + gameutils.count, 200, 120);
                gimage.drawstring("胜利", 400, 500);
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    void logic() {
        //关卡难度
        if (gameutils.count < 5) {
            gameutils.level = 0;
            myfish.level = 1;
        } else if (gameutils.count <= 15) {
            gameutils.level = 1;
        } else if (gameutils.count <= 50) {
            gameutils.level = 2;
            myfish.level = 2;
        } else if (gameutils.count <= 150) {
            gameutils.level = 3;
            myfish.level = 3;
        } else if (gameutils.count <= 300) {
            gameutils.level = 4;
            myfish.level = 3;
        } else { //分数大于300,玩家胜利
            state = 3;
        }

        //......
    }
}

13.界面优化

实现游戏界面积分、难度、关卡的可视化编写

在工具类中定义绘制文字的方法

//绘制文字的方法
public static void drawword(graphics g, string str, color color, int size, int x, int y) {
    g.setcolor(color);
    g.setfont(new font("仿宋", font.bold, size));
    g.drawstring(str, x, y);
}

在背景类中让积分、难度、我方鱼等级可视化

public class bg {
    void paintself(graphics g, int fishlevel) {
        g.drawimage(gameutils.bgimg, 0, 0, null);
        switch (gamewin.state) {
            case 0:
                gameutils.drawword(g, "请点击开始游戏", color.red, 80, 500, 500);
                break;
            case 1:
                gameutils.drawword(g, "积分:" + gameutils.count, color.orange, 50, 200, 120);
                gameutils.drawword(g, "难度:" + gameutils.level, color.orange, 50, 600, 120);
                gameutils.drawword(g, "等级:" + fishlevel, color.orange, 50, 1000, 120);
                break;
            case 2:
                break;
            case 3:
                gameutils.drawword(g, "积分:" + gameutils.count, color.orange, 50, 200, 120);
                gameutils.drawword(g, "难度:" + gameutils.level, color.orange, 50, 600, 120);
                gameutils.drawword(g, "等级:" + fishlevel, color.orange, 50, 1000, 120);
                gameutils.drawword(g, "胜利", color.red, 80, 700, 500);
                break;
            default:
                break;
        }
    }
}

对窗口类的 paint 方法进行优化

@override
public void paint(graphics g) {
    //懒加载模式初始化对象
    offscreenimage = createimage(width, height);
    graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象
    bg.paintself(gimage, myfish.level);  //***********************

    //游戏状态:0未开始,1游戏中,2游戏失败,3游戏胜利,4游戏暂停,5重新开始
    switch (state) {
        case 0:
            break;
        case 1:
            myfish.paintself(gimage);
            logic();        //不断添加敌方鱼类
            for (enamy enamy : gameutils.enamylist) {
                enamy.paintself(gimage);
            }
            break;
        case 2:
            break;
        case 3: //玩家胜利
            myfish.paintself(gimage);
            break;
        case 4:
            break;
        default:
            break;
    }

    //将绘制好的图片一次性绘制到主窗口中
    g.drawimage(offscreenimage, 0, 0, null);
}

14.右侧敌方鱼和多种敌方鱼的生成

首先实现右侧敌方小鱼的生成,在工具类中添加右侧敌方小鱼的图

//敌方鱼类
public static image enamy_l_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish1_r.gif");
public static image enamy_r_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish1_l.gif");

在敌方鱼类中创建敌方小鱼右类继承敌方小鱼左类

//右敌方鱼类
class enamy_1_r extends enamy_1_l {
    enamy_1_r() {
        this.x = 1400;
        dir = -1;
        this.img = gameutils.enamy_r_img;
    }
}

在窗口类中定义随机数,使左右敌方小鱼随机出现

public class gamewin extends jframe {
    //......

    //定义一个随机数,以此让左右鱼的数量随机
    double random;

    //......

        random = math.random();

        //每重绘10次生成一条敌方鱼类
        if (time % 10 == 0) {
            if (random > 0.5) {
                enamy = new enamy_1_l();
            } else {
                enamy = new enamy_1_r();
            }
            gameutils.enamylist.add(enamy);
        }

        //......
}

接下来是其他敌方鱼类的生成,其原理与敌方小鱼的生成原理一致

在窗口类添加敌方鱼图

//敌方鱼类
public static image enamy_l_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish1_r.gif");
public static image enamy_r_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish1_l.gif");
public static image enamy_l_2img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish2_r.png");
public static image enamy_r_2img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish2_l.png");
public static image enamy_l_3img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish3_r.png");
public static image enamy_r_3img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\fish3_l.png");

创建剩下的敌方鱼类并写入参数

class enamy_2_l extends enamy {
    enamy_2_l() {
        this.x = -100;
        this.y = (int) (math.random() * 700 + 100);
        this.width = 100;
        this.height = 100;
        this.speed = 5;
        this.count = 2;
        this.type = 2;
        this.img = gameutils.enamy_l_2img;
    }
}

class enamy_2_r extends enamy_2_l {
    enamy_2_r() {
        this.x = 1400;
        dir = -1;
        this.img = gameutils.enamy_r_2img;
    }
}

class enamy_3_l extends enamy {
    enamy_3_l() {
        this.x = -300;
        this.y = (int) (math.random() * 700 + 100);
        this.width = 300;
        this.height = 150;
        this.speed = 15;
        this.count = 5;
        this.type = 3;
        this.img = gameutils.enamy_l_3img;
    }
	
	//由于第3种鱼的体积过大,我们需要将其修改一下
    public rectangle getrec() {
        return new rectangle(x + 40, y + 30, width - 80, height - 60);
    }
}

class enamy_3_r extends enamy_3_l {
    enamy_3_r() {
        this.x = 1400;
        dir = -1;
        this.img = gameutils.enamy_r_3img;
    }
}

在窗口类种添加敌方鱼的生成,添加我方鱼和敌方鱼的等级比较来判断游戏是否失败,同时游戏失败界面只剩下敌方鱼类

public class gamewin extends jframe {
    //......

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象
        bg.paintself(gimage, myfish.level);

        //游戏状态:0未开始,1游戏中,2游戏失败,3游戏胜利,4游戏暂停,5重新开始
        switch (state) {
            case 0:
                break;
            case 1:
                myfish.paintself(gimage);
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                break;
            case 2:
            	//*********游戏失败界面*********
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                break;
            case 3: //玩家胜利
                myfish.paintself(gimage);
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    void logic() {
        //......

        random = math.random();

		//********根据游戏等级生成鱼类********
        switch (gameutils.level) {
            case 4:
            case 3:
            case 2:
                if (time % 30 == 0) {
                    if (random > 0.5) {
                        enamy = new enamy_3_l();
                    } else {
                        enamy = new enamy_3_r();
                    }
                    gameutils.enamylist.add(enamy);
                }
            case 1:
                if (time % 20 == 0) {
                    if (random > 0.5) {
                        enamy = new enamy_2_l();
                    } else {
                        enamy = new enamy_2_r();
                    }
                    gameutils.enamylist.add(enamy);
                }
            case 0:
                //每重绘10次生成一条敌方鱼类
                if (time % 10 == 0) {
                    if (random > 0.5) {
                        enamy = new enamy_1_l();
                    } else {
                        enamy = new enamy_1_r();
                    }
                    gameutils.enamylist.add(enamy);
                }
                break;
            default:
                break;
        }


        //移动方向
        for (enamy enamy : gameutils.enamylist) {
            enamy.x = enamy.x + enamy.dir * enamy.speed;

            //我方鱼与敌方鱼的碰撞检测
            if (myfish.getrec().intersects(enamy.getrec())) {
            	//********如果我方鱼的等级大于等于敌方鱼*******
                if (myfish.level >= enamy.type) { 
                    enamy.x = -200;
                    enamy.y = -200;
                    //得分
                    gameutils.count += enamy.count;
                } else {
                    state = 2;
                }
            }
        }
    }
}

背景类优化:

public class bg {
    void paintself(graphics g, int fishlevel) {
        g.drawimage(gameutils.bgimg, 0, 0, null);
        switch (gamewin.state) {
            case 0 -> gameutils.drawword(g, "请点击开始游戏", color.red, 80, 500, 500);
            case 1 -> {
                gameutils.drawword(g, "积分:" + gameutils.count, color.orange, 50, 200, 120);
                gameutils.drawword(g, "难度:" + gameutils.level, color.orange, 50, 600, 120);
                gameutils.drawword(g, "等级:" + fishlevel, color.orange, 50, 1000, 120);
            }
            case 2 -> {
                gameutils.drawword(g, "积分:" + gameutils.count, color.orange, 50, 200, 120);
                gameutils.drawword(g, "难度:" + gameutils.level, color.orange, 50, 600, 120);
                gameutils.drawword(g, "等级:" + fishlevel, color.orange, 50, 1000, 120);
                gameutils.drawword(g, "失败", color.red, 80, 600, 500);
            }
            case 3 -> {
                gameutils.drawword(g, "积分:" + gameutils.count, color.orange, 50, 200, 120);
                gameutils.drawword(g, "难度:" + gameutils.level, color.orange, 50, 600, 120);
                gameutils.drawword(g, "等级:" + fishlevel, color.orange, 50, 1000, 120);
                gameutils.drawword(g, "胜利", color.red, 80, 700, 500);
            }
            default -> {
            }
        }
    }
}

15.boss鱼的添加

在工具类中添加敌方 boss 鱼

public static image boss_img = toolkit.getdefaulttoolkit().createimage("d:\\idea\\idea_demo\\fishgame\\images\\enemyfish\\boss.gif");

创建敌方 boss 鱼类继承父类

class enamy_boss extends enamy {
    enamy_boss() {
        this.x = -1000;
        this.y = (int) (math.random()*700 + 100);
        this.width = 340;
        this.height = 340;
        this.speed = 100;
        this.count = 0;
        this.type = 10;
        this.img = gameutils.boss_img;
    }
}

在窗口类中获取敌方 boss 鱼类,在游戏等级为 4 的代码块中,添加 boss 生成的条件,同时对 boss 和我方鱼类及其他鱼类碰撞的情况做出处理

public class gamewin extends jframe {
    //......

    //敌方boss类
    enamy boss;
    //是否生成boss
    boolean isboss = false;

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        //......
    }

    @override
    public void paint(graphics g) {
        //懒加载模式初始化对象
        offscreenimage = createimage(width, height);
        graphics gimage = offscreenimage.getgraphics();     //获取图片对应的画笔对象
        bg.paintself(gimage, myfish.level);

        //游戏状态:0未开始,1游戏中,2游戏失败,3游戏胜利,4游戏暂停,5重新开始
        switch (state) {
            case 0:
                break;
            case 1:
                myfish.paintself(gimage);
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                //********boss鱼的生成********
                if (isboss) {
                    boss.x += boss.dir * boss.speed;
                    boss.paintself(gimage);
                    if (boss.x < 0) {
                        gimage.setcolor(color.red);
                        gimage.fillrect(boss.x, boss.y, 2400, boss.height / 30);
                    }
                }
                break;
            case 2:
                logic();        //不断添加敌方鱼类
                for (enamy enamy : gameutils.enamylist) {
                    enamy.paintself(gimage);
                }
                //********添加敌方boss********
                if (isboss) {
                    boss.paintself(gimage);
                }
                break;
            case 3: //玩家胜利
                myfish.paintself(gimage);
                break;
            case 4:
                break;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    void logic() {
        //关卡难度
        if (gameutils.count < 5) {
            gameutils.level = 0;
            myfish.level = 1;
        } else if (gameutils.count <= 15) {
            gameutils.level = 1;
        } else if (gameutils.count <= 50) {
            gameutils.level = 2;
            myfish.level = 2;
        } else if (gameutils.count <= 150) {
            gameutils.level = 3;
            myfish.level = 3;
        } else if (gameutils.count <= 300) {
            gameutils.level = 4;
            myfish.level = 3;
        } else { //分数大于300,玩家胜利
            state = 3;
        }

        random = math.random();

        switch (gameutils.level) {
            case 4:
            	//********判断是否生成boss********
                if (time % 60 == 0) {
                    if (random > 0) {
                        boss = new enamy_boss();
                        isboss = true;
                    }
                }
            case 3:
            case 2:
                //......
            case 1:
               //......
            case 0:
                //......
            default:
                break;
        }


        //移动方向
        for (enamy enamy : gameutils.enamylist) {
            enamy.x = enamy.x + enamy.dir * enamy.speed;

            //********boss鱼的碰撞处理********
            if (isboss) {
                if (boss.getrec().intersects(enamy.getrec())) {
                    enamy.x = -200;
                    enamy.y = -200;
                }
                if (boss.getrec().intersects(myfish.getrec())) {
                    state = 2;
                }
            }

            //......
        }
    }
}

16.游戏暂停功能和重新开始功能的实现

首先实现暂停功能,如果游戏状态为 4,则游戏暂停,我们使用空格键来实现游戏暂停功能

在 launch 方法中添加键盘的监听事件

public class gamewin extends jframe {
    //......

    //创建一个启动窗口,设置窗口信息
    public void launch() throws interruptedexception {
        //......

        //键盘移动
        this.addkeylistener(new keyadapter() {
            @override//按压
            public void keypressed(keyevent e) {
                //上下左右四个键的ascii值为 上 ↑:38下 ↓: 40左 ←: 37右 →: 39
                if (e.getkeycode() == 38) {
                    gameutils.up = true;
                }
                if (e.getkeycode() == 40) {
                    gameutils.down = true;
                }
                if (e.getkeycode() == 37) {
                    gameutils.left = true;
                }
                if (e.getkeycode() == 39) {
                    gameutils.right = true;
                }
                //********空格键********
                if (e.getkeycode() == 32) {
                    //如果游戏状态为运行中,则暂停,反之
                    switch (state) {
                        case 1:
                            state = 4;
                            gameutils.drawword(getgraphics(), "游戏暂停!!!", color.red, 50, 600, 400);
                            break;
                        case 4:
                            state = 1;
                            break;
                    }
                }
            }

            @override//抬起
            public void keyreleased(keyevent e) {
                if (e.getkeycode() == 38) {
                    gameutils.up = false;
                }
                if (e.getkeycode() == 40) {
                    gameutils.down = false;
                }
                if (e.getkeycode() == 37) {
                    gameutils.left = false;
                }
                if (e.getkeycode() == 39) {
                    gameutils.right = false;
                }
            }
        });

        //背景图片重复使用,需要重复调用repaint方法
        while (true) {
            repaint();
            time++;
            thread.sleep(40);
        }
    }

    @override
    public void paint(graphics g) {
        //......
            case 4:
            	//********
                return;
            default:
                break;
        }

        //将绘制好的图片一次性绘制到主窗口中
        g.drawimage(offscreenimage, 0, 0, null);
    }

    //批量添加鱼类
    ......
}

接下来是重新开始功能,在窗口类中创建一个新的方法,将游戏状态恢复到初始,然后定义在游戏状态为结束或胜利的情况下,点击鼠标左键进入重新开始界面

//重新开始
void regame() {
    gameutils.enamylist.clear();
    time =0;
    myfish.level = 0;
    gameutils.count = 0;
    myfish.x = 700;
    myfish.y = 500;
    myfish.width = 50;
    myfish.height = 50;
    boss = null;
    isboss = false;
}
//创建一个启动窗口,设置窗口信息
public void launch() throws interruptedexception {
    //......

    //添加鼠标监听事件
    this.addmouselistener(new mouseadapter() {
        @override
        public void mouseclicked(mouseevent e) {
            if (e.getbutton() == 1 && state == 0) {
                state = 1;
                repaint();
            }
            //重新开始
            if (e.getbutton() == 1 && (state == 2 || state == 3)) {
                regame();
                state = 1;
            }
        }
    });

    //键盘移动
    //......
}

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