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• 句法
• 范例
• 规范
• 浏览器兼容性
• 另请参阅
• 相关话题

update() 方法在 ServiceWorkerRegistration interface attempts to update the service worker. It fetches the worker's script URL, and if the new worker is not byte-by-byte identical to the current worker, it installs the new worker. The fetch of the worker bypasses any browser caches if the previous fetch occurred over 24 hours ago.

注意 : This feature is available in Web 工作者 .

句法

serviceWorkerRegistration.update();
					

参数

None.

返回值

A Promise that resolves with a ServiceWorkerRegistration 对象。

范例

The following simple example registers a service worker example then adds an event handler to a button so you can explicitly update the service worker whenever desired:

if ('serviceWorker' in navigator) {
  navigator.serviceWorker.register('/sw-test/sw.js', {scope: 'sw-test'}).then(function(registration) {
    // registration worked
    console.log('Registration succeeded.');
    button.onclick = function() {
      registration.update();
    }
  }).catch(function(error) {
    // registration failed
    console.log('Registration failed with ' + error);
  });
};
					

规范

规范	状态	注释
服务工作者 The definition of 'ServiceWorkerRegistration.update()' in that specification.	工作草案	初始定义。

浏览器兼容性

The compatibility table in this page is generated from structured data. If you'd like to contribute to the data, please check out https://github.com/mdn/browser-compat-data and send us a pull request. 更新 GitHub 上的兼容性数据

	桌面						移动
	Chrome	Edge	Firefox	Internet Explorer	Opera	Safari	Android webview	Chrome for Android	Firefox for Android	Opera for Android	Safari on iOS	Samsung Internet
update	Chrome 45 45 Starting with Chrome 46, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Chrome 48, this method always bypassed the browser cache. Starting with Chrome 48, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.	Edge 17 17 16 Disabled Disabled From version 16: this feature is behind the Enable service workers preference.	Firefox 44 44 Extended Support Releases (ESR) before Firefox 78 ESR do not support service workers and the Push API.	IE No	Opera 32 32 Starting with Opera 33, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Opera 35, this method always bypassed the browser cache. Starting with Opera 35, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.	Safari 11.1	WebView Android 45 45 Starting with Chrome 46, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Chrome 48, this method always bypassed the browser cache. Starting with Chrome 48, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.	Chrome Android 45 45 Starting with Chrome 46, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Chrome 48, this method always bypassed the browser cache. Starting with Chrome 48, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.	Firefox Android 44	Opera Android 32 32 Starting with Opera 33, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Opera 35, this method always bypassed the browser cache. Starting with Opera 35, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.	Safari iOS No	Samsung Internet Android 4.0 4.0 Starting with Samsung Internet 5.0, update() returns a promise that resolves with 'undefined' if the operation completed successfully or there was no update, and rejects if update failed. If the new worker ran but installation failed, the promise still resolves. Formerly, it raised an exception. Before Samsung Internet 5.0, this method always bypassed the browser cache. Starting with Samsung Internet 5.0, it only bypasses the cache when the previous service worker check was more than twenty-four hours ago.

图例

完整支持

完整支持

不支持

不支持

实验。期望将来行为有所改变。

实验。期望将来行为有所改变。

见实现注意事项。

用户必须明确启用此特征。

用户必须明确启用此特征。

另请参阅

• 使用服务工作者
• 服务工作者基本代码范例
• ServiceWorker 就绪了吗？
• Promise
• Using web workers

元数据

• 最后修改： 2020 年 8 月 24 日

相关话题

1. 服务工作者 API
2. ServiceWorkerRegistration
3. 特性

   1. active
   2. installing
   3. navigationPreload
   4. onupdatefound
   5. periodicSync
   6. pushManager
   7. scope
   8. sync
   9. waiting
4. 方法

   1. getNotifications()
   2. showNotification()
   3. unregister()
   4. update()
5. 继承：

   1. EventTarget
6. Related pages for Service Workers API

   1. 缓存
   2. CacheStorage
   3. Client
   4. Clients
   5. ExtendableEvent
   6. FetchEvent
   7. InstallEvent
   8. Navigator.serviceWorker
   9. NotificationEvent
   10. PeriodicSyncEvent
   11. PeriodicSyncManager
   12. PeriodicSyncRegistration
   13. ServiceWorker
   14. ServiceWorkerContainer
   15. ServiceWorkerGlobalScope
   16. SyncEvent
   17. SyncManager
   18. SyncRegistration
   19. WindowClient