具有3个独立文件的Javascript继承
嗨,我有3个javascript文件:Game.js、Player.js、Drawable.js。 现在在Game.js中,我想创建一个对象&u播放器,它是可绘制的,而不是播放器。这意味着player是一个player对象,它是一个扩展Drawable的类 Drawable.js具有3个独立文件的Javascript继承,javascript,html,inheritance,Javascript,Html,Inheritance,嗨,我有3个javascript文件:Game.js、Player.js、Drawable.js。 现在在Game.js中,我想创建一个对象&u播放器,它是可绘制的,而不是播放器。这意味着player是一个player对象,它是一个扩展Drawable的类 Drawable.js function Drawable(x, y, src) { this.x = x; this.y = y; this.img = new Image(); this.img.src = src;
function Drawable(x, y, src)
{
this.x = x;
this.y = y;
this.img = new Image();
this.img.src = src;
this.width = this.img.width;
this.height = this.img.height;
this.draw = function(canvas)
{
canvas.drawImage(this.img,this.x, this.y);
}
this.midpoint = function()
{
return {
x: this.x + this.width/2,
y: this.y + this.height/2};
}
}
}
function Player()
{
this.moveLeft = function()
{
this.x -= 3;
}
this.moveRight = function()
{
this.x += 3;
}
this.moveUp = function()
{
this.y -= 3;
}
this.moveDown = function()
{
this.y += 3;
}
}
var _player;
_player = new Player();
_player.draw(...);
_player.moveLeft();
...
...
Player.js
function Drawable(x, y, src)
{
this.x = x;
this.y = y;
this.img = new Image();
this.img.src = src;
this.width = this.img.width;
this.height = this.img.height;
this.draw = function(canvas)
{
canvas.drawImage(this.img,this.x, this.y);
}
this.midpoint = function()
{
return {
x: this.x + this.width/2,
y: this.y + this.height/2};
}
}
}
function Player()
{
this.moveLeft = function()
{
this.x -= 3;
}
this.moveRight = function()
{
this.x += 3;
}
this.moveUp = function()
{
this.y -= 3;
}
this.moveDown = function()
{
this.y += 3;
}
}
var _player;
_player = new Player();
_player.draw(...);
_player.moveLeft();
...
...
Game.js
function Drawable(x, y, src)
{
this.x = x;
this.y = y;
this.img = new Image();
this.img.src = src;
this.width = this.img.width;
this.height = this.img.height;
this.draw = function(canvas)
{
canvas.drawImage(this.img,this.x, this.y);
}
this.midpoint = function()
{
return {
x: this.x + this.width/2,
y: this.y + this.height/2};
}
}
}
function Player()
{
this.moveLeft = function()
{
this.x -= 3;
}
this.moveRight = function()
{
this.x += 3;
}
this.moveUp = function()
{
this.y -= 3;
}
this.moveDown = function()
{
this.y += 3;
}
}
var _player;
_player = new Player();
_player.draw(...);
_player.moveLeft();
...
...
这就是我想做的。我试着把Player.prototype=新的Drawable;但它不起作用。我该怎么办?如果您希望玩家对象的行为能够调用
player.draw(...);
player.moveLeft(...);
然后,draw
和moveLeft
函数需要作为属性存储在每个玩家对象(yikes)或玩家对象原型链的某个位置
这就引出了一条关于实际代码的注释:这些函数应该在原型中,而不是在实际对象中
所以,为了回答你的实际问题
- 您应该做的第一件事是将方法放置在原型中
- 然后,您需要使一个玩家的原型成为所有可拖动的原型
Player.prototype = Object.create(Drawable.prototype);
在创建具有新播放器的播放器之前,请执行此操作。
:)
附录
--它还向您展示了如何使用“构造函数”来构建一个具有初始x和y的播放器。Coffeescript是一种具有基于类的对象模型的语言,该模型在javascript的原型对象模型之上建模。在他们的页面上,您可以看到coffeescript编译为javascript时的一个示例。您可能没有考虑到这一点。也许你从来没有想过这件事,但是为什么不制作一个
可绘制的组件,通过依赖注入,在构建期间或之后不久,将其提供给玩家呢
var Drawable = function () { ... };
var Player = function () { ... };
var player = new Player(new Drawable(), new Controlable(), new Physical());