iphone不支持onbeforeunload

无线组遇到个问题 提交的时候会有个loading浮层 然后页面跳转 当点后退的时候 浮层还在 。我想在onbeforeunload上加个事件清理就好了，结果发现iphone上这个事件不执行。google之 原来 原来iphone有pageshow pagehide事件

 

 window.addEventListener("pageshow", myLoadHandler, false);
 window.addEventListener("pagehide", myUnloadHandler, false);

    function myLoadHandler(evt)
    {
        if (evt.persisted) {
            // This is actually a pageshow event and the page is coming out of the Page Cache.
            // Make sure to not perform the "one-time work" that we'd normally do in the onload handler.
            ...

            return;
        }

        // This is either a load event for older browsers,
        // or a pageshow event for the initial load in supported browsers.
        // It's safe to do everything my old load event handler did here.
        ...
    }

    function myUnloadHandler(evt)
    {
        if (evt.persisted) {
            // This is actually a pagehide event and the page is going into the Page Cache.
            // Make sure that we don't do any destructive work, or work that shouldn't be duplicated.
            ...

            return;
        }

        // This is either an unload event for older browsers,
        // or a pagehide event for page tear-down in supported browsers.
        // It's safe to do everything my old unload event handler did here.
        ...
    }

    if ("onpagehide" in window) {
        window.addEventListener("pageshow", myLoadHandler, false);
        window.addEventListener("pagehide", myUnloadHandler, false);
    } else {
        window.addEventListener("load", myLoadHandler, false);
        window.addEventListener("unload", myUnloadHandler, false);
    }
原文 http://www.webkit.org/blog/516/webkit-page-cache-ii-the-unload-event/