javascript 模拟坦克大战游戏(html5版)附源码下载

一、总结关键点和遇到的问题

1.javascript中的继承，最好父类只提供方法共享，属性写到各自子类中，避免父类和子类的构造函数混杂。

2.prototype模拟继承的代码，应写在所有方法定义之前，否则原型对象被改变，方法就变成了未定义，如：

复制代码代码如下:

 
Hero.prototype = new Tank (0, 0, 0); 
Hero.prototype.constructor = Hero; 
Hero.prototype.addLife = function(){ 
this.lifetimes++; 
document.querySelector("#life").innerHTML = hero.lifetimes; 
} 

3.canvas画图形时，除了画矩形，其他的都要加上 ctx.beginPath();、ctx.closePath();，否则会出现意想不到的错误。

4.concat函数可以合并数组，或者是元素返回一个新的数组

5.Image的src属性赋值后就会加载图片，但如果没有加载完毕就画图片，会导致失效，所以使用onload事件处理

6.扩展Array功能，删除指定元素

复制代码代码如下:

 
//扩展 删除指定元素 
Array.prototype.deleteElement = function (obj) { 
if (obj) { 
for (var i = 0; i if (this[i] === obj) { 
this.splice (i, 1); 
} 
} 
} 
} 

7.定时器设置，setInterval（“fun”,1000）方法的第一个参数，可以是字符串，如"hero.say()",类似eval会去执行这串代码，所以它可以给函数带上参数，并且也指定了这个函数的运行上下文。但如果传入是函数的句柄，则不能带参数，并且不能指定上下文，除了第一种方式解决外，我用了闭包来解决这个问题

复制代码代码如下:

 
//定时器，自行运动 
this.timer = setInterval ((function (context) { 
return function () { 
Bullet.prototype.move.call (context) 
} 
}) (this), 30); 

我保存了当前的执行环境，并调用call方法手动执行。

8.方法的功能设计，除了功能外，应该包括执行此功能的条件检测，如move，就应该包括什么情况下可以移动，移动到什么地方就不能移动了。此检测不应该放在外部。

9.写代码时不应该去想设计或者优化的问题，先实现功能，再谈优化，或者先设计再实现。思路要清晰，别混乱，着重于一点。

10.javascript中没有sleep的功能，可以创建一个变量作为缓冲，来达到间隔执行的目的

二、代码实现

1.本程序分为Bomb.js,Bullet.js,Draw.js,Tank.js,index.html,img,music,

2.最终效果

3.代码

1.index.html

复制代码代码如下:

按下回车键开始游戏

按下1键增加生命,默认是1

剩余生命数 :1

2.Draw.js

复制代码代码如下:

 
/** 
* Created by Alane on 14-3-18. 
*/ 

function draw(){ 
//检测子弹和坦克生死 
checkDead(); 
//清空画布 
ctx.clearRect(0,0,500,400); 
//画玩家 
if(!hero.isdead){ 
drawTank(hero); 
}else{ 
hero.cutLife(); 
} 
//画敌人坦克 
for (var i = 0; i drawTank(enemys[i]); 
} 
//画敌人子弹 
for(var j=0;jvar temp = enemys[j].bulletsList; 
for (var i = 0; i drawBullet(temp[i]); 
} 
} 
//画玩家子弹 
var temp = hero.bulletsList; 
for (var i = 0; i drawBullet(temp[i]); 
} 

//画炸弹 
for(var i=0;idrawBown(Bombs[i]); 
} 

} 

function drawTank(tank){ 
var x = tank.x; 
var y = tank.y; 
ctx.fillStyle = tank.color; 

if(tank.direct == 0 || tank.direct ==2){ 
ctx.fillRect(x, y, 5,30); 
ctx.fillRect(x+15, y, 5,30); 

ctx.fillRect(x+6, y+8, 8,15); 

ctx.strokeStyle = tank.color; 
ctx.lineWidth = '1.5'; 
if(tank.direct == 0){ 
ctx.beginPath(); 
ctx.moveTo(x+10,y-2); 
ctx.lineTo(x+10,y+8); 
ctx.closePath(); 
}else{ 
ctx.beginPath(); 
ctx.moveTo(x+10,y+24); 
ctx.lineTo(x+10,y+32); 
ctx.closePath(); 
} 

ctx.stroke(); 
}else{ 
ctx.fillRect(x, y, 30,5); 
ctx.fillRect(x, y+15, 30,5); 

ctx.fillRect(x+8, y+6, 15,8); 

ctx.strokeStyle = '#FF0000'; 
ctx.lineWidth = '1.5'; 
if(tank.direct == 3){ 
ctx.beginPath(); 
ctx.moveTo(x-2,y+10); 
ctx.lineTo(x+8,y+10); 
ctx.closePath(); 
}else{ 
ctx.beginPath(); 
ctx.moveTo(x+24,y+10); 
ctx.lineTo(x+32,y+10); 
ctx.closePath(); 
} 

ctx.stroke(); 
} 

} 
function drawBullet(bullet){ 
ctx.fillStyle = bullet.color; 
ctx.beginPath(); 
ctx.arc(bullet.x,bullet.y,2,360,true); 
ctx.closePath(); 
ctx.fill(); 
} 

function drawBown (obj){ 
if(obj.life>8){ 
ctx.drawImage(im,obj.x,obj.y,50,50); 
}else if(obj.life>4){ 
ctx.drawImage(im2,obj.x,obj.y,50,50); 
}else{ 
ctx.drawImage(im3,obj.x,obj.y,50,50); 
} 

obj.lifeDown(); 
if(obj.lifeBombs.deleteElement(obj); 
} 
} 

function checkDead(){ 
//检测敌人子弹生死 
for(var j=0;jvar temp = enemys[j].bulletsList; 
for (var i = 0; i var o = temp[i]; 
if(o.isdead){ 
temp.deleteElement(o); 
} 
} 
} 
//检测玩家子弹生死 
var temp = hero.bulletsList; 
for (var i = 0; i var o = temp[i]; 
if(o.isdead){ 
temp.deleteElement(o); 
} 
} 

//检测敌人坦克生死 
for (var i = 0; i var o = enemys[i]; 
if(o.isdead){ 
enemys.deleteElement(o); 
} 
} 
} 

Bomb.js

复制代码代码如下:

 
/** 
* Created by Alane on 14-3-18. 
*/ 
function Bomb(x,y){ 
this.life = 12; 
this.x = x; 
this.y = y; 
} 
Bomb.prototype.lifeDown = function(){ 
this.life--; 
} 

Tank.js

复制代码代码如下:

 
/** 
* Created by Alane on 14-3-7. 
*/ 
/** 
* direct 0 上 
* 1 右 
* 2 下 
* 3 左 
* @param x 
* @param y 
* @param direct 
* @constructor 
*/ 
//******************************************************************************************/ 
//坦克父类 
function Tank (x, y, direct) { 
this.speed = 2; 

} 
Tank.prototype.moveUp = function () { 
//边界检测 
if (this.y //换方向 
this.changeDirect (); 
return; 
} 
this.y -= this.speed; 
this.direct = 0; 

} 
Tank.prototype.moveDown = function () { 
if (this.y > height - 30) { 
this.changeDirect (); 
return; 
} 
this.y += this.speed; 
this.direct = 2; 
} 
Tank.prototype.moveLeft = function () { 
if (this.x this.changeDirect (); 
return; 
} 
this.x -= this.speed; 
this.direct = 3; 

} 
Tank.prototype.moveRight = function () { 
if (this.x > width - 30) { 
this.changeDirect (); 
return; 
} 
this.x += this.speed; 
this.direct = 1; 

} 

//变换方向 
Tank.prototype.changeDirect = function () { 
while (true) { 
var temp = Math.round (Math.random () * 3); 
if (this.direct != temp) { 
this.direct = temp; 
break; 
} 
} 
//alert("x="+this.x+" y="+this.y+" direct="+this.direct) 
} 

//射击子弹 
Tank.prototype.shot = function () { 
if(this.isdead){ 
return; 
} 
if (this.bulletsList.length //新建子弹 
var bullet = null; 
switch (this.direct) { 
case 0: 
bullet = new Bullet (this.x + 10, this.y - 2, 0, this.color); 
break; 
case 1: 
bullet = new Bullet (this.x + 32, this.y + 10, 1, this.color); 
break; 
case 2: 
bullet = new Bullet (this.x + 10, this.y + 32, 2, this.color); 
break; 
case 3: 
bullet = new Bullet (this.x - 2, this.y + 10, 3, this.color); 
break; 
} 
//放入弹夹 
this.bulletsList.push (bullet); 
} 
} 
//******************************************************************************************/ 
//玩家 
function Hero (x, y, direct) { 
this.lifetimes = 5; 
this.isdead = false; 
this.color = '#FF0000'; 
this.x = x; 
this.y = y; 
this.direct = direct; 
this.bulletsList = []; 
this.maxBulletSize = 10; 
this.newlife = null; 
} 
Hero.prototype = new Tank (0, 0, 0); 
Hero.prototype.constructor = Hero; 
Hero.prototype.addLife = function(){ 
this.lifetimes++; 
document.querySelector("#life").innerHTML = hero.lifetimes; 
} 
Hero.prototype.cutLife = function(){ 
if(this.lifetimes>=1 && !this.newlife){ 
this.lifetimes--; 
this.newlife = setTimeout("hero.newLife()",2000); 
} 
} 
Hero.prototype.newLife = function(){ 
this.isdead = false; 
clearTimeout(hero.newlife); 
hero.newlife = null; 
document.querySelector("#life").innerHTML = hero.lifetimes; 
} 


//******************************************************************************************/ 
//敌人坦克 
function Enemy (x, y, direct) { 
this.isdead = false; 
this.color = 'blue'; 
this.x = x; 
this.y = y; 
this.direct = direct; 
this.bulletsList = []; 
this.maxBulletSize = 1; 


//定时器,自动移动 
this.timer1 = setInterval ((function (context) { 
return function () { 
//移动 
Enemy.prototype.move.call (context); 
} 
}) (this), 30); 

//定时器,射击 
this.timer2 = setInterval ((function (context) { 
return function () { 
//射击 
Tank.prototype.shot.call (context); 
} 
}) (this), 2000); 

//定时器,变换方向 
this.timer3 = setInterval ((function (context) { 
return function () { 
//射击 
Tank.prototype.changeDirect.call (context); 
} 
}) (this), 3000); 
} 

Enemy.prototype = new Tank (0, 0, 0); 
Enemy.prototype.constructor = Enemy; 
Enemy.prototype.move = function () { 
switch (this.direct) { 
case 0: 
this.moveUp (); 
break; 
case 1: 
this.moveRight (); 
break; 
case 2: 
this.moveDown (); 
break; 
case 3: 
this.moveLeft (); 
break; 
} 
} 

Bullet.js

复制代码代码如下:

 
/** 
* Created by Alane on 14-3-11. 
*/ 
function Bullet (x, y, direct, color) { 
this.isdead = false; 
this.x = x; 
this.y = y; 
this.direct = direct; 
this.speed = 4; 
this.color = color; 
//定时器，自行运动 
this.timer = setInterval ((function (context) { 
return function () { 
Bullet.prototype.move.call (context) 
} 
}) (this), 30); 
} 
Bullet.prototype.move = function () { 
switch (this.direct) { 
case 0: 
this.y -= this.speed; 
break; 
case 1: 
this.x += this.speed; 
break; 
case 2: 
this.y += this.speed; 
break; 
case 3: 
this.x -= this.speed; 
break; 
} 

//边界检测 
if (this.y  width || this.y > height || this.x clearInterval (this.timer); 
this.isdead = true; 
} 

//碰撞检测 检测敌人坦克 
for(var i=0;ivar temp = allTank[i]; 
if(temp.isdead){ 
continue; 
} 
switch (temp.direct){ 
case 0: 
case 2:if(this.x>temp.x && this.xtemp.y&& this.yif(this.color == temp.color){ 
break; 
} 
Bombs.push(new Bomb(temp.x-10,temp.y-10)); 
clearInterval (this.timer); 
this.isdead = true; 
temp.isdead = true; 
}break 
case 1: 
case 3:if(this.x>temp.x && this.xtemp.y&& this.yif(this.color == temp.color){ 
break; 
} 
Bombs.push(new Bomb(temp.x-10,temp.y-10)); 
clearInterval (this.timer); 
this.isdead = true; 
temp.isdead = true; 
}break; 
} 
} 

} 