Angular Service Worker DataGroups maxAge无法正常工作

如何解决Angular Service Worker DataGroups maxAge无法正常工作

我有一个角度应用程序，正在使用服务工作者，并且正在使用“ dataGroups”为图像的特定URL设置“ maxAge”。

我的问题是，即使映像已过期，也正在从服务人员加载该映像，并且我将“策略”设置为“新鲜”。

这是我的“ ngsw-config.json”文件：

{
  "$schema": "./node_modules/@angular/service-worker/config/schema.json","index": "/index.html","assetGroups": [
    {
      "name": "app","installMode": "prefetch","resources": {
        "files": [
          "/favicon.ico","/index.html","/*.css","/*.js"
        ]
      }
    },{
      "name": "assets","installMode": "lazy","updateMode": "prefetch","resources": {
        "files": [
          "/assets/**","/*.(eot|svg|cur|jpg|png|webp|gif|otf|ttf|woff|woff2|ani)"
        ]
      }
    }
  ],"dataGroups": [
    {
      "name" : "imagecaching","cacheConfig" : {
        "maxAge": "20s","strategy" : "freshness","timeout" : "3m","maxSize" : 100
      },"urls" : [
        "https://www.lifewire.com/thmb/ahpDeQ36tu-_rIkvJuKehIUbRbk=/768x0/filters:no_upscale():max_bytes(150000):strip_icc()/GettyImages-831864150-5c32ba8b46e0fb0001b18e2b-32fd8792359f4acd973b4bd6c24e999e.jpg"
      ]
    }
  ]
}

您能解释一下什么时候从网络而不是服务人员处加载图像吗？