Question

Problem

尝试制作一个简单的Chrome扩展程序，用于跟踪您在网页上停留的时间。我一直遇到很多麻烦。当我运行扩展时，调试器会经历一个循环，说它无法设置null的innerhtml，因为它无法找到id为elapsedTime的元素。在调试器中，当我检查文档时，元素不在那里。我认为这与未点击图标时未加载的html有关，但我不确定如何处理这个问题。但是无论哪种方式！任何帮助表示赞赏。

分别是

background.js，manifest.json和index.html

＆＃13;

chrome.tabs.onUpdated.addListener(function(tabId, changeInfo, tab){
    if (tab.status == 'complete') {
        let startDate = new Date();
        let elapsedTime = 0;

        setInterval(function() {
                timeNow = new Date();
                elapsedTime = timeNow - startDate;
                document.getElementById('elapsedTime').innerHTML = elapsedTime;
        },100);
    };
});

＆＃13;

{
  "name": "Timer-Extension",
  "description": "A timer that displays how long you have been on a page",
  "version": "0.1",
  "manifest_version": 2,
  "browser_action": {
    "default_icon": "src/img/clock-16.png",
    "default_popup": "src/index.html",
    "default_title": "Timer-Extension"
  },
  "icons": {
    "16": "src/img/clock-16.png",
    "48": "src/img/clock-48.png",
    "128": "src/img/clock-128.png"
  },
  "permissions": [
    "tabs"
  ],
  "background": {
    "scripts": ["src/js/background.js"]
  }
}

＆＃13;

<html>
    <body>
        <p id = 'elapsedTime'></p>
        <script type='text/javascript' src = js/background.js></script>
    </body>
</html>

＆＃13;

getElementById在Chrome扩展程序中返回Null

0 个答案: