我是Java语言的新手，我正在尝试编写一个涉及移动块的简单游戏。块由继承MBlocks类的类createjs.Container表示，我添加了一个名为select的方法，如果传递了true，则该方法应将块中的圆圈的颜色变为红色。如果通过false，则为灰色。在init()函数中这可以正常工作，但是当我尝试通过击键事件调用该函数时，控制台会告诉我select方法不存在。不起作用的行在reactKey函数中，如下所示：mBlocks[activeID].select(true);。我已经在下面发布了代码。我无法确定这是变量范围还是具有继承性或完全其他类的类的问题。任何的建议都受欢迎。
<!DOCTYPE html>
<html>
<head>
<title>M-Blocks Game</title>
<link href="../_shared/demo.css" rel="stylesheet" type="text/css">
<script src="http://code.createjs.com/easeljs-0.7.0.min.js"></script>
<script class="jsbin" src="http://ajax.googleapis.com/ajax/libs/jquery/1/jquery.min.js"></script>
<script>
var stage, mBlocks, bkgd;
var sw, sh;
var activeID;
//MBlock class inherits from Container. MBlocks are squares that in addition to Container
//properties have velocity and rotational velocity and can be either active or inactive
//and selected or not selected
var MBlock = function (x,y,color) {
this.initialize(x,y,color);
};
MBlock.prototype = new createjs.Container();
MBlock.prototype.Container_initialize = MBlock.prototype.initialize;
MBlock.prototype.initialize = function(x,y,color) {
this.Container_initialize();
this.x = x;
this.y = y;
this.selected = false;
this.color = color;
this.lightCol = "#DDD";
//Create and draw block
this.block = new createjs.Shape();
this.block.graphics.beginFill(this.color).drawRoundRect(x,y,30,30,7);
this.addChild(this.block);
//Create and draw light bulb
this.light = new createjs.Shape();
this.light.graphics.beginFill("#DDD").drawCircle(this.x+15,this.y+15,5);
this.addChild(this.light);
};
MBlock.prototype.select = function(sel) {
this.select = sel;
this.light.graphics.clear();
this.lightCol = "red";
if (sel) this.lightCol = "red";
else this.lightCol = "#DDD";
this.light.graphics.beginFill(this.lightCol).drawCircle(this.x+15,this.y+15,5);
};
function init() {
stage = new createjs.Stage("demoCanvas");
sw = stage.canvas.width;
sh = stage.canvas.height;
activeID = 0;
bkgd = new createjs.Shape();
bkgd.graphics.beginFill("#DDF").drawRoundRect(0,0,sw,sh,7);
stage.addChild(bkgd);
mBlocks = [];
mBlocks.push(new MBlock(0,0,"#0F0"));
mBlocks.push(new MBlock(35,0,"#0F0"));
activeID = 1;
mBlocks[1].select(true);
stage.addChild(mBlocks[0],mBlocks[1]);
stage.update();
}
function reactKey(event) {
if(event.keyCode==32) { //space key--switch between selection of active mBlocks
mBlocks[activeID].select(false);
activeID += 1;
if (activeID >= mBlocks.length) activeID = 0;
mBlocks[activeID].select(true);
stage.update();
}
}
function reactKeyUp(event) {
//Code here
}
function onTick(){
//Code here
}
</script>
最佳答案
你在叫init吗？...
在发布的代码中，您永远不会调用init，因此，在这种情况下，您还没有定义mBlocks数组。
也许您可以执行以下操作（如果您仍然希望使用init函数，否则可以使用IIFE）
function init() {
//init code
}
init();
使用IIFE
(function(){
//init code
})();
最后的建议...停止思考“类” ... javascript中没有这样的事情...最多您拥有构造函数，该函数创建具有相似结构（创建模式）的对象...停止思考静态类然后开始思考动态定义。
编辑
在注释中解决了这个问题一段时间之后，我们终于在select方法中发现了一个错字。
原始代码，带有错别字：
MBlock.prototype.select = function(sel) {
this.select = sel; //Here was the problem
//more code
};
更正的代码：
MBlock.prototype.select = function(sel) {
this.selected = sel;
//more code
};