扩展项目的组成
了解构成 Manifest V3 浏览器扩展的标准文件和文件夹，以及每一项的作用。
扩展项目的组成 是 CoddyKit 上的免费 Browser Extensions Development (Chrome & Edge) 课时。 这是第 4 节课，共 4 节。 你可以在下方免费阅读本课时的完整内容 — 然后在浏览器中使用内置代码编辑器和全天候 AI 导师进行实践。 这是 Browser Extensions Development (Chrome & Edge) 学习路径的一部分，你的进度在网页和 CoddyKit 应用中同步。 Browser Extensions Development (Chrome & Edge) 课程共包含 4 节课。
本课时的部分内容尚未翻译，以英文显示。
Extensions Are Just Web Files
An extension is just a bundle of HTML, CSS, JavaScript, and a config file, which the browser loads in a special, extra-capable context.
The manifest.json Heart
Every extension needs a manifest.json at its root — it declares name, version, permissions, and scripts. Without it, the browser ignores the folder.
{
"manifest_version": 3,
"name": "My Extension",
"version": "1.0.0"
}A Typical Folder Structure
Layout is flexible, but a clean folder structure stays maintainable: manifest at root, plus popup, background, content, and icons folders.
The Background Service Worker
In Manifest V3, background logic runs as a service worker. It handles events even with no UI open, but unloads when idle to save memory.
{
"background": {
"service_worker": "background.js"
}
}The Popup Action
The action defines the toolbar button and the popup it opens — itself just a tiny HTML page. The config below shows both fields.
{
"action": {
"default_popup": "popup/popup.html",
"default_title": "Open My Extension"
}
}Content Scripts
Content scripts run inside web pages so your extension can read and modify the DOM. You scope them with URL match patterns.
{
"content_scripts": [{
"matches": ["https://*.example.com/*"],
"js": ["content/main.js"]
}]
}Icons in Multiple Sizes
Provide your icon in several sizes — browsers show it in different places at different resolutions, so it stays crisp everywhere.
{
"icons": {
"16": "icons/icon16.png",
"48": "icons/icon48.png",
"128": "icons/icon128.png"
}
}Declaring Permissions
The permissions array lists the browser APIs you need, like storage or tabs. Request only what you actually use.
{
"permissions": ["storage", "activeTab"]
}Web-Accessible Resources
If a web page must load a file packaged in your extension, list it under web_accessible_resources — otherwise the browser blocks access.
{
"web_accessible_resources": [{
"resources": ["images/logo.png"],
"matches": ["https://*.example.com/*"]
}]
}How Pieces Communicate
Popup, content scripts, and service worker live in separate contexts, so they talk via the messaging API, not shared variables.
chrome.runtime.sendMessage({ type: 'PING' })Keeping It Organized
As it grows, group related files into folders and keep manifest.json lean. A predictable layout makes debugging and store review easier.
Quick Check
Check what you remember about extension structure.
Recap
You toured the building blocks: manifest.json declares all, a service worker runs background, the action drives the popup, content scripts touch pages.
常见问题解答
「扩展项目的组成」课时是免费的吗？
是的 — 「扩展项目的组成」的完整文本可在网页上免费阅读。要进行交互式练习（内置代码编辑器和全天候 AI 导师）并解锁 Browser Extensions Development (Chrome & Edge) 课程的其余内容，请升级到 CoddyKit PRO。 Browser Extensions Development (Chrome & Edge) 课程共包含 4 节课。
「扩展项目的组成」这节课中我会学到什么？
了解构成 Manifest V3 浏览器扩展的标准文件和文件夹，以及每一项的作用。 你通过在浏览器中直接运行的动手代码来练习 Browser Extensions Development (Chrome & Edge)，全天候 AI 导师会在你学习这节课的过程中回答你的问题。
学习 Browser Extensions Development (Chrome & Edge) 需要有经验吗？
无需任何先前经验。CoddyKit 上的 Browser Extensions Development (Chrome & Edge) 课程适合初学者到高级学习者，你可以从这里开始或从头开始，按照自己的节奏学习。 这是第 4 节课，共 4 节。
「扩展项目的组成」课时需要多长时间？
大多数 CoddyKit 课程大约需要 5–10 分钟。每节课都很精短且互动，所以你能稳步进步，并在网页和应用中从离开的地方继续。
我能在这节 Browser Extensions Development (Chrome & Edge) 课中编写并运行代码吗？
能。每节 Browser Extensions Development (Chrome & Edge) 课都包含内置代码编辑器，你可以在浏览器中直接编写并运行真实代码，并获得即时 AI 反馈 — 无需本地设置。