在JavaScript中使用“this”对象

Question

我试图像这样声明一个JavaScript对象：

var Calculator = function() {
    this.textbox = new Textbox({
        ...
    });
    this.btn1 = new Button ({
        ...
        onClick: function() {
            this.textbox.value += "1";
    });
    ...
};

我做了一些调试，发现this内的this.btn1对象不再引用Calculator对象。如何将textbox引用到Calculator的{​​{1}}？

非常感谢提前！

Answer 1

var self = this

的旧技巧

var Calculator = function() {
    var self = this;  // self is a reference to calculator, always.

    this.textbox = new Textbox({
        ...
    });
    this.btn1 = new Button ({
        ...
        onClick: function() {
            self.textbox.value += "1";
    });
    ...
};