google-chrome-extension - Chrome扩展程序将Background.js中的消息发送到内容脚本

Question

我已经阅读了有关如何执行将消息从后台javascript文件(main.js)发送到内容脚本(content.js)的文档，但无法获取onMessage来打开警报。

Manifest.json

{
   "name": "Example",
   "version": "1.0.1",
   "manifest_version" : 2,
   "description": "Example Description",
   "background" : {
     "scripts" : ["main.js"]
   },
   "page_action" : {
      "default_icon": {
         "19": "icons/19.png",
         "38": "icons/38.png"
      },
      "default_title" : "Example Title"
   },
   "content_scripts": [{
      "matches": ["<all_urls>"],
      "js": ["lib/jquery-1.8.3.min.js","scripts/content.js"],
      "run_at": "document_idle",
      "all_frames": false
   }],
   "permissions": [
       "tabs",
       "geolocation"
   ],
   "icons": {
       "16": "icons/16.png",
       "48": "icons/48.png",
       "128": "icons/48.png"
   }

}

背景javascript文件(main.js)

chrome.tabs.query({active: true, currentWindow: true}, function(tabs){
    chrome.tabs.sendMessage(tabs[0].id, {action: "SendIt"}, function(response) {});  
});

内容javascript文件(content.js)

chrome.extension.onMessage.addListener(function(msg, sender, sendResponse) {
   if (msg.action == 'SendIt') {
      alert("Message recieved!");
   }
});

Answer 1

由于@Teepeemm的洞察力，我在将消息发送到内容脚本之前包含了一个制表符加载完成功能。

等待标签完全加载

chrome.tabs.onUpdated.addListener(function (tabId, changeInfo, tab) {          
   if (changeInfo.status == 'complete') {   
      chrome.tabs.query({active: true, currentWindow: true}, function(tabs){
         chrome.tabs.sendMessage(tabs[0].id, {action: "SendIt"}, function(response) {});  
      });
   }
});