Flutter web 新版本更新提示

添加这段代码到 项目/web/index.html

即可,大概是 116行

  if (serviceWorker.state == 'activated') {
    console.log('Installed new service worker.');
    loadMainDartJs();
            // if there's an existing controller (previous Service Worker), show the prompt
          // you can tweak this and delay the notification once the page is load you can show a notification and ask for a new refresh
              if (navigator.serviceWorker.controller) {
                // you have a better UI here, reloading is not a great user experince here.
                const confirmed = alert('New version of the app is available. Refresh now');
                if (confirmed == true) {
                  window.location.reload();
                }
          }
  }
});