在 ES6 class 语句中访问回调中的 class 成员

Question

重要我使用的是 ES6 class 语句。关于用函数定义的 "classes" 的答案不适用，因为 class 语句中不允许使用类似 var this = that 的内容。我在这方面看到的答案不起作用。回调之外的变量不可见。

WebPageReader.Storage = class {
  constructor(object) {
    this.Object = object;
    var self = this; // self is out of scope when constructor completes
  }

  // var self = this; // not allowed here

  Load() {
    chrome.storage.sync.get('somesetting',
      function (setting) {
        console.log(this.Object); // I need to do something with this.Object defined at the class level, but this points to something besides my class.
      }
    );
  }
}

Answer 1

您可以关注以下两者之一：

  Load() {
    const that = this;

    chrome.storage.sync.get('somesetting',
      function (setting) {
        console.log(that.Object);
      }
    );
  }

或

  Load() {
    chrome.storage.sync.get('somesetting',
      setting => {
        console.log(this.Object);
      }
    );
  }

参考文献：

https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Functions/Arrow_functions

在 ES6 class 语句中访问回调中的 class 成员

Access class member within callback when inside ES6 class statement

javascript

es6-class