backbone.js - 主干集合 URL 未定义

Question

尝试将 url 传递给 fetchFromURL 函数，但登录时 URL 未定义。不知道为什么会这样！！

class Device extends Backbone.Model

class Devices extends Backbone.Collection
    model: Device
    localStorage: new Backbone.LocalStorage 'devices'
    url: "http://192.168.2.17:8030/profile/RestProfile.svc/GetDeviceList/"
    fetchFromURL: =>
        collection = @
        console.log @url

getView = =>
    devices = new Devices
    devices.fetch()
    devices.fetchFromURL()