Question

我必须通过Chrome扩展程序在Google搜索页面中添加div 我的inject.js文件如下：

var body=document.getElementById("search");

//creates bar and creates bar removal function
var bar = document.createElement("DIV");
function removeBar(){
  bar.remove();
}

//styles bar
var ds = bar.style;
ds.position = "fixed";
ds.width = "512px";
ds.height = "33px";
ds.background = "rgba(0,0,0,0.86)";
ds.zIndex = "9999999999999";

//creates X button and makes it so clicking it runs the removeBar() function
var x = document.createElement("BUTTON");
x.onclick = removeBar;
bar.appendChild(x);

//styles button
var xs = x.style;
xs.background = "black";
xs.borderColor = "black";
xs.color = "rgba(255,255,255,.86)";
xs.position = "fixed";
xs.left = "100%";
xs.marginTop = "5px";
xs.marginLeft = "-29px"

//puts X in button
var xtext = document.createTextNode("X");
x.appendChild(xtext);

//puts bar in page
body.insertBefore(bar, body.children[0]);

我的manifest.json如下：

{
  "manifest_version": 2,
  "name": "Inject script in webpage",
  "version": "2.0.1",
  "description": "inject script in webpage.",

  "icons": {
    "48" : "sample-48.png",
    "128" : "sample-128.png"
  },
  "content_scripts": [
    {
      "matches": ["https://www.google.com.pk/*"],
      "js" : ["inject.js"],
      "all_frames": true
    }
  ]
}

但是当我加载google SERP页面时，错误消息显示有点像“无法调用”insertBefore“属性为null”，似乎变量“body”未定义。通过谷歌页面的检查元素我检查了ID为“搜索”的DIV存在，如果我做错了那么plzz让我知道我是chrome扩展开发的新手

Answer 1

问题可能在这里：

var body=document.getElementById("search");

＆＃34;身体＆＃34;变量为空 - 可能是因为您要查找的ID不存在。尝试寻找其他一些id（我用过＆＃34; gbqfb＆＃34;）。但是，您应该学习使用Chrome的内置调试器来找出您的代码无法正常工作的原因，而不是在这里为您提供答案。看看这个youtube视频：

https://www.youtube.com/watch?v=htZAU7FM7GI

chrome扩展中的内容脚本

1 个答案: