Window: sự kiện pagehide

Cú pháp

Sử dụng tên sự kiện trong các phương thức như addEventListener(), hoặc thiết lập thuộc tính trình xử lý sự kiện.

addEventListener("pagehide", (event) => { })

onpagehide = (event) => { }

Kiểu sự kiện

A PageTransitionEvent. Inherits from Event.

Event properties

PageTransitionEvent.persisted Read only

Indicates if the document is loading from a cache.

Event handler aliases

In addition to the Window interface, the event handler property onpagehide is also available on the following targets:

• HTMLBodyElement
• HTMLFrameSetElement
• SVGSVGElement

Ghi chú sử dụng

Like the unload and beforeunload events, this event is not reliably fired by browsers, especially on mobile. For example, the pagehide event is not fired at all in the following scenario:

1. A mobile user visits your page.
2. The user then switches to a different app.
3. Later, the user closes the browser from the app manager.

However, unlike the unload and beforeunload events, this event is compatible with the back/forward cache (bfcache), so adding a listener to this event will not prevent the page from being included in the bfcache.

The best event to use to signal the end of a user's session is the visibilitychange event. In browsers that don't support visibilitychange the pagehide event is the next-best alternative.

If you're specifically trying to detect page unload events, the pagehide event is the best option.

See the Page Lifecycle API guide for more information about how this event relates to other events in the page lifecycle.

Ví dụ

In this example, an event handler is established to watch for pagehide events and to perform special handling if the page is being persisted for possible reuse.

window.addEventListener("pagehide", (event) => {
  if (event.persisted) {
    /* the page isn't being discarded, so it can be reused later */
  }
});

This can also be written using the onpagehide event handler property on the Window:

window.onpagehide = (event) => {
  if (event.persisted) {
    /* the page isn't being discarded, so it can be reused later */
  }
};

Đặc tả kỹ thuật

Tính tương thích trên trình duyệt

Xem thêm

• The pageshow event.
• Page Lifecycle API gives best-practices guidance on handling page lifecycle behavior in your web applications.
• PageLifecycle.js: a JavaScript library that deals with cross-browser inconsistencies in page lifecycle behavior.
• Back/forward cache explains what the back/forward cache is, and its implications for various page lifecycle events.