fix: 翻译 Web Worker

aio/content/guide/web-worker.md

@@ -1,18 +1,43 @@
 # Using Web Workers with Angular CLI
 
+# 通过 Angular CLI 使用 Web Worker
+
+
 [Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) allow you to run CPU intensive computations in a background thread, freeing the main thread to update the user interface.
 
+[Web Workers](https://developer.mozilla.org/en-US/docs/Web/API/Web_Workers_API) 允许你在后台线程中运行 CPU 密集型计算，解放主线程，以便更新用户界面。
+
+
 If you find your application becomes unresponsive while processing data, using Web Workers can help.
 
+如果你发现你的应用在处理数据时停止了响应，那么使用 Web Workers 可以为你提供帮助。
+
+
 ## Adding a Web Worker
 
+## 添加一个 Web Worker
+
+
 You can add a web worker anywhere in your application. If the file that contains your expensive computation is `src/app/app.component.ts`, you can add a Web Worker using `ng generate web-worker app`.
 
+你可以在应用中的任何地方添加一个 Web Worker。假设包含沉重计算工作的文件是 `src/app/app.component.ts`，你可以使用 `ng generate web-worker app` 新增一个 Web Worker。
+
+
 Running this command will:
 
+运行这个命令会：
+
+
 - configure your project to use Web Workers, if it isn't already.
+
+  把你的项目配置成使用 Web Workers 的（如果尚未配置过）。
+
+
 - add `src/app/app.worker.ts` with scaffolded code to receive messages:
 
+  添加 `src/app/app.worker.ts` 文件，并添加用于接收消息的脚手架代码：
+
+
   ```typescript
   addEventListener('message', ({ data }) => {
     const response = `worker response to ${data}`;
@@ -22,6 +47,9 @@ Running this command will:
 
 - add scaffolded code to `src/app/app.component.ts` to use the worker:
 
+  往 `src/app/app.component.ts` 中添加使用该 worker 的脚手架代码：
+
+
   ```typescript
   if (typeof Worker !== 'undefined') {
     // Create a new
@@ -38,9 +66,23 @@ Running this command will:
 
 After the initial scaffolding, you will need to refactor your code to use the Web Worker by sending messages to and from.
 
+在完成了最初的脚手架之后，你需要重构代码，通过来回发送消息来使用 Web Worker。
+
 ## Caveats
 
+## 警告
+
+
 There are two important things to keep in mind when using Web Workers in Angular projects:
 
+在 Angular 项目中使用 Web Workers 时，要记住两个重要事项：
+
+
 - Some environments or platforms, like `@angular/platform-server` used in [Server-side Rendering](guide/universal), don't support Web Workers. You have to provide a fallback mechanism to perform the computations that the worker would perform to ensure your application will work in these environments.
+
+  某些环境或平台（比如[服务端渲染](guide/universal)中使用的 `@angular/platform-server` 不支持 Web Workers。你必须提供一个后备机制来执行 Worker 要执行的计算，以确保你的应用能在那些环境中运行。
+
 - Running Angular itself in a Web Worker via [**@angular/platform-webworker**](api/platform-webworker) is not yet supported in Angular CLI.
+
+  Angular CLI 尚不支持通过 [**@angular/platform-webworker**](api/platform-webworker)在 Web Worker 中运行 Angular 自身。
+