此处的问题是，出于安全目的，用户/网页脚本(非特权脚本)无法访问JavaScript API，而browser，chrome JavaScript API的一部分，只能由特权脚本(例如Web扩展程序的后台脚本和内容脚本)访问(同样，内容脚本不能访问所有JavaScript API).基本上，如果您需要将数据从网页脚本发送到后台脚本，则应使用CustomEvent将数据发送到充当桥的内容脚本，然后使用browser.runtime.sendMessage从那里将数据发送到后台脚本. PFB示例代码

The issue here is that user/webpage scripts (unprivileged scripts) don't have access to JavaScript API for security purposes and browser, chrome are part of JavaScript APIs which can only be accessed by privileged scripts like web extension's background scripts and content scripts (again content scripts don't have access to all the JavaScript APIs). Basically, if you need to send data from web page script to background script, CustomEvent should be used to send data to a content script which acts as a bridge and from there send that data to background script using browser.runtime.sendMessage. PFB sample code

window.onload = function(){
    document.dispatchEvent(new CustomEvent("myEvent",{
        detail:["Hello","World"]
    }));
}

contentscript.js

contentscript.js

document.addEventListener("myEvent", function (event) {
browser.runtime.sendMessage({
    data: event.detail
});

background.js

background.js

browser.runtime.onMessage.addListener(function (message) {
     data = message.data;
     // do stuff
});