sendMessage from popup to content.js not working in chrome extension

问题

I'm trying to make a popup interface for a chrome extension. I can't seem to send a message from the popup.html/popup.js to the content.js script. Here's what I have so far. When I click on the extension icon I get a button that says clickme. I click it and nothing happens, no errors in the chrome javascript console, and no message to content.js.

Manifest

{
"content_security_policy": "script-src 'self' 'unsafe-eval'; object-src 'self'",
  "manifest_version": 2,
  "name": "extensiontest",
  "version": "0.2",
  "content_scripts": [
  {
    "matches": [
      "<all_urls>"
    ],
    "js": ["content.js"]
  }
],
"browser_action": {
  "default_icon": "Beaker.png",
    "default_popup":"popup.html"
},
"background": {
  "scripts": ["background.js"]
},
"permissions": [
    "tabs"
  ]
}

popup.html

<html>
<head></head>
<script src="popup.js"></script>
<body>
<input id="button1" type=button value=clickme>
</body></html>

popup.js

function popup(){
    alert(1);
      chrome.tabs.query({active: true, currentWindow: true}, function(tabs) {
    var activeTab = tabs[0];
    chrome.tabs.sendMessage(activeTab.id, {"message": "start"});
  });

button1=document.getElementById("button1");
button1.addEventListener('click', popup)
}

content.js

   chrome.runtime.onMessage.addListener(
      function(request, sender, sendResponse) {
        if( request.message === "start" ) {
         start();
             }
      }
    );

    function start(){
        alert("started");
    }

回答1:

I modified your popup.js and used DOMContentLoaded as Chrome extension suggested like:

popup.js:

 function popup() {
    chrome.tabs.query({currentWindow: true, active: true}, function (tabs){
    var activeTab = tabs[0];
    chrome.tabs.sendMessage(activeTab.id, {"message": "start"});
   });
}

document.addEventListener("DOMContentLoaded", function() {
  document.getElementById("button1").addEventListener("click", popup);
});

content.js:

chrome.runtime.onMessage.addListener(
      function(request, sender, sendResponse) {
        if( request.message === "start" ) {
         start();
             }
      }
    );

    function start(){
        alert("started");
    }

popup.html:

<!DOCTYPE html>
<html>
<head></head>
<script src="popup.js"></script>
<body>
<input id="button1" type=button value=clickme>
</body></html>

I've tested on my end it works.

来源：https://stackoverflow.com/questions/29926598/sendmessage-from-popup-to-content-js-not-working-in-chrome-extension

标签

google-chrome-extension

popup

sendmessage