javascript - 在javascript类函数中调用函数？

Question

我试图向特定的 js 类声明属性和函数。但是当我尝试在函数内部调用函数时(即使在声明后调用)它会抛出异常

未捕获类型错误:对象 [object Object] 没有方法“addButtonEventListeners”

列出我的代码:SplashScene.js

var anim1, background;
var SplashScene;

function SplashScreen(SceneContainer)
{
this.name = "SplashScreen";
this.loadScreen = function()
{

    background = new createjs.Shape();
    background.graphics.beginBitmapFill(loader.getResult("gameLoopSplash")).drawRect(0,0,w,h);
    SplashScene = new createjs.Container();

    anim1 = new createjs.Sprite(buttonData, "playIdle");
    anim1.framerate = 30;
    anim1.x = 260;
    anim1.y = 22;
    SplashScene.alpha = 0;

    SplashScene.addChild(background);
    SplashScene.addChild(anim1);
}

this.addButtonEventListeners =  function()
{
    console.log("addButtonEventListeners   SplashScreen" );
}

this.menuIn = function()
{
    console.log("menuIn   SplashScreen" );
    stage.addChild(SplashScene);
    var tween = createjs.Tween.get(SplashScene).to({y : 0, x : 0, alpha : 1}, 5000).call(this.menuInCompleted);
    var splashTimer = window.setTimeout(function(){menuOut("MainScreen", false)},15000);

}

this.menuInCompleted = function()
{
    console.log("menuInCompleted   SplashScreen" );
    this.addButtonEventListeners();
}
}

谁能告诉我该怎么做？

Answer 1

问题是 setTimeout 回调中的上下文 (this) 是 window，而不是您的对象。

你可以改变

var splashTimer = window.setTimeout(function(){menuOut("MainScreen", false)},15000);

至

var splashTimer = window.setTimeout(
     (function(){menuOut("MainScreen", false)}).bind(this)
,15000);

并且您还必须在绑定(bind) menuIn (到事件？)时执行相同的操作。