javascript – tabs.getCurrent()结果是未定义的？

不知道为什么当我导航到例如amazon.com或google.com并点击浏览器图标进行浏览器操作时,我无法使用getCurrent()检索有关当前选项卡的信息.我缺少什么提示？

表现：

{
  "name": "testGetCurrentTab",
  "version":  "1.0",
  "description":  "",
  "manifest_version": 2,

  "icons": {
    "48": "icons/icon-48.png"
  },

  "permissions": [
      "tabs",
      "<all_urls>"
  ],

  "browser_action": {
      "default_icon": "icon/icon-32.png"
  },

  "background": {
      "scripts": ["background.js"]
  }      
}

背景：

function displayInfo() {

  function onGot(tabInfo) {
    console.log('Inside onGot() ...');
    console.log(tabInfo);
  }

  function one rror(error) {
    console.log(`Error: ${error}`);
  }

  var gettingCurrent = browser.tabs.getCurrent();
  gettingCurrent.then(onGot, one rror);
}

browser.browserAction.onClicked.addListener(displayInfo);

这是输出：

Inside onGot() ...  background.js:4:7

undefined  background.js:5:7

Firefox开发版54(64位)

https://developer.mozilla.org/en-US/Add-ons/WebExtensions/API/tabs/getCurrent

解决方法:

来自MDN tabs.getCurrent()：

Get a 07001 containing information about the tab that this script is running in.

You can call this function in contexts where there is a browser tab, such as an 07002. If you call it from a background script or a popup, it will return undefined.

browserAction.onClicked事件返回活动选项卡,您不需要其他API调用.

browser.browserAction.onClicked.addListener(function(tab) {
 console.log(tab)
})

见tab parameter for browserAction.onClicked listener.