javascript - 如何从 Javascript 的内部函数访问父对象？

Question

我通过以下方式声明了一个类:

function maskEditor() {
    this.init();
};

maskEditor.prototype = {
    foo: null,
    container: new createjs.Container(),

    init:function () {
        this.foo = "bar";
        this.container.on("mousedown", this.onMouseDown); // This is just an easeljs event dispatcher
    },

    onMouseDown: function (event) {
        alert(this.foo); // WRONG. 'this' is out of the scope :(
    }
};

长话短说:我使用easeljs库，并且我已经声明了一个事件调度程序来捕获鼠标点击。我需要从该方法内部访问 maskEditor 对象。我怎样才能做到这一点？

Answer 1

您需要将上下文绑定(bind)到事件处理程序:

this.container.on("mousedown", this.onMouseDown.bind(this));