window.onbeforeunload = function () { return "你還沒有完成你的文章，就這樣離開了嗎？"; }; window.addEventListener("beforeunload", function (e) { var ... ... <看更多>

window.onbeforeunload = function() {return "are you sure?"} Will work, ... ... <看更多>

window.onbeforeunload = function (e) {. e = e || window.event;. // For IE and Firefox prior to version 4. if (e) {. e.returnValue = 'Any string';. }. ... <看更多>

Summary · The beforeunload event is fired before the webpage and its resources are about to unload. · Use beforeunload to confirm if users really want to leave ... ... <看更多>

From what I can tell, you can't use the beforeunload event because the framework does whatever it does in a way that breaks this event. ... <看更多>

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Code Preview. window.onbeforeunload = function () { clearTimeout(reload_timeout); window.onbeforeunload = old_before; if_unload_callback(); if (old_before) ... ... <看更多>