javascript - 方法 createjs.Stage 使用画架返回错误

Question

当我获取 Canvas 并发送创建舞台时，我收到此字符串错误:

Uncaught TypeError: Cannot call method 'addEventListener' of undefined.

我的初始化函数:

function init() {
    canvas = document.getElementById("testCanvas");

    stage = new createjs.Stage(canvas);
    screen_width = canvas.width;
    screen_height = canvas.height;

    contentManager = new ContentManager();
    contentManager.SetDownloadCompleted(startGame);
    contentManager.StartDownload();
}

给出错误的代码块是:

p.enableDOMEvents = function(enable) {
    if (enable == null) { enable = true; }
    var n, o, ls = this._eventListeners;
    if (!enable && ls) {
        for (n in ls) {
            o = ls[n];
            o.t.removeEventListener(n, o.f);
        }
        this._eventListeners = null;
    } else if (enable && !ls) {
        var t = window.addEventListener ? window : document;
        var _this = this;
        ls = this._eventListeners = {};
        ls["mouseup"] = {t:t, f:function(e) { _this._handleMouseUp(e)} };
        ls["mousemove"] = {t:t, f:function(e) { _this._handleMouseMove(e)} };
        ls["dblclick"] = {t:t, f:function(e) { _this._handleDoubleClick(e)} };
        t = this.canvas;
        if (t) { ls["mousedown"] = {t:t, f:function(e) { _this._handleMouseDown(e)} }; }

        for (n in ls) {
            o = ls[n];
            o.t.addEventListener(n, o.f);
        }
    }

尤其是这个 block :

    for (n in ls) {
        o = ls[n];
        o.t.addEventListener(n, o.f);
    }

当'n'的值为BitmapAnimation_initialize时，给出错误。我在Stage.js中找到了这段代码，该文件附带easeljs v0.6.0的rar

Answer 1

如果您注释掉 contentManager 代码，您是否会看到此错误？看起来很奇怪。