如何获取javascript中的chrome选项卡源代码

如何获取javascript中的chrome选项卡源代码,javascript,google-chrome,google-chrome-extension,tabs,Javascript,Google Chrome,Google Chrome Extension,Tabs,我尝试开发一个chrome扩展,我需要能够获得当前选项卡的源代码,因此我遵循chrome示例,我有三个文件: manifest.json: { "manifest_version": 2, "name": "Source code getter", "description": "This extension is a test to get current tab source code", "version": "0.1", "browser_acti

我尝试开发一个chrome扩展,我需要能够获得当前选项卡的源代码,因此我遵循chrome示例,我有三个文件:

manifest.json:

{
    "manifest_version": 2,
    "name": "Source code getter",
    "description": "This extension is a test to get current tab source code",
    "version": "0.1",
    "browser_action": {
         "default_icon": "icon.png",
        "default_popup": "popup.html"
    }, 
    "permissions": [
        "tabs"
  ]
}
popup.html:

<!doctype html>
 <html>
    <head>
        <title>Get source popup</title>
         <style>
             body {
                min-width: 357px;
                min-height: 357px;
                overflow-x: hidden;
            }
        </style>
        <script src="popup.js"></script>
     </head>
    <body>
    </body>
</html>
我通过在网上搜索来构建popup.js,我必须承认我真的不知道sendMessage是如何工作的,但我认为第二个参数ask the source code必须在function response的参数中返回,但它没有,以下是js日志:

430 popup.js:4
> Error in event handler for (unknown): Cannot read property 'html' of undefined
> Stack trace: TypeError: Cannot read property 'html' of undefined
>    at chrome-extension://boefdmhphdcngpckofecmjnihbgphmch/popup.js:7:35
>    at disconnectListener (extensions::messaging:338:9)
>    at Function.target.(anonymous function) (extensions::SafeBuiltins:19:14)
>    at EventImpl.dispatchToListener (extensions::event_bindings:397:22)
>    at Function.target.(anonymous function) (extensions::SafeBuiltins:19:14)
>    at Event.publicClass.(anonymous function) [as dispatchToListener] (extensions::utils:93:26)
>    at EventImpl.dispatch_ (extensions::event_bindings:379:35)
>    at EventImpl.dispatch (extensions::event_bindings:403:17)
>    at Function.target.(anonymous function) (extensions::SafeBuiltins:19:14)
>    at Event.publicClass.(anonymous function) [as dispatch] (extensions::utils:93:26) 

所以我得到了正确的标签,但是我没有得到正确的响应表单sendMessage函数,有人可以解释为什么?谢谢。

从您的清单判断,您没有听到您发送的消息

清单中未定义内容脚本,因此页面中未加载任何内容;弹出代码中没有executeScript调用,因此不会加载任何内容

因此,不需要处理您的消息,并且调用回调时会出现一个错误集。您的消息{action:getHtml}并没有神奇的意义;您需要在页面的一侧有一个脚本来接收它并形成响应

您需要的是一个将为chrome.runtime.onMessage添加侦听器的应用程序,它将处理您的请求。我们称之为content.js。然后你可以这样做:

chrome.tabs.executeScript({code: "content.js"}, function() {
  if(chrome.runtime.lastError) {
    console.error(chrome.runtime.lastError.message);
    return;
  }
  chrome.tabs.sendMessage(tab.id, {action: "getHtml"}, function(response) {
    /* process response */
  });
});
相应content.js的代码超出了本问题的范围。也请看一下,它很好地介绍了内容脚本的工作原理

chrome.tabs.executeScript({code: "content.js"}, function() {
  if(chrome.runtime.lastError) {
    console.error(chrome.runtime.lastError.message);
    return;
  }
  chrome.tabs.sendMessage(tab.id, {action: "getHtml"}, function(response) {
    /* process response */
  });
});