Chrome扩展程序:无法在后台脚本和内容脚本之间传递消息

Question

我本质上是试图通过使用localStorage后台脚本中的对象来获得我的chrome扩展的持久存储.

这是设置:

我有一个后台脚本和一个内容脚本.内容脚本需要从扩展名中获取/设置数据localStorage.

但是,我无法收到要发送到后台脚本的消息.

这是后台脚本中的代码:

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
  console.log(sender.tab ? "from a content script:" + sender.tab.url : "from the extension");
  if (request.greeting == "hello")
    sendResponse({farewell: "goodbye"});
});

和内容脚本:

setTimeout(function () {
  chrome.runtime.sendMessage({greeting: "hello"}, function(response) {
    console.log(response.farewell);
  });
}, 5000);

理想情况下,后台脚本应输出from a content script: [some url],内容脚本应输出goodbye.相反,我得到以下错误:

Port: Could not establish connection. Receiving end does not exist. 

任何帮助/建议表示赞赏!

谢谢 :)

编辑:清单

{
  "manifest_version": 2,

  "name": "Helios",
  "description": "Helios chrome extension.",
  "version": "0.0.1",

  "permissions": [
    "https://secure.flickr.com/",
    "storage"
  ],

  "background": {
    "page": "background.html"
  },

  "browser_action": {
    "default_icon": {
      "19": "img/icon-19.png",
      "38": "img/icon-38.png"
    },
    "default_title": "Helios",
    "default_popup": "popup.html"
  },

  "content_scripts":[
    {
      "matches": ["*://*/*"],
      "css": ["css/main.css"],
      "js": [
        "js/vendor/jquery-1.9.1.js",
        "js/vendor/handlebars-1.0.0-rc.4.js",
        "js/vendor/ember-1.0.0-rc.7.js",
        "js/vendor/d3.v3.js",
        "js/vendor/socket.io.min.js",
        "js/templates.js",
        "js/main.js"
      ],
      "run_at": "document_end"
    }
  ],

  "web_accessible_resources": [
    "img/**",
    "fonts/**"
  ]
}

修改:Chrome版本

Google Chrome   29.0.1547.65 (Official Build 220622) 
OS  Mac OS X 
Blink   537.36 (@156661)
JavaScript  V8 3.19.18.19
Flash   11.8.800.170
User Agent  Mozilla/5.0 (Macintosh; Intel Mac OS X 10_8_3) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/29.0.1547.65 Safari/537.36

Answer 1

来自onMessage文档.

当事件侦听器返回时,此函数变为无效,除非您从事件侦听器返回true以指示您希望异步发送响应(这将使消息通道保持打开到另一端,直到调用sendResponse).

所以你的代码应该是这样的

chrome.runtime.onMessage.addListener(function(request, sender, sendResponse) {
  console.log(sender.tab ? "from a content script:" + sender.tab.url : "from the extension");
  if (request.greeting == "hello") {
    sendResponse({farewell: "goodbye"});
    return true;
  }
});