js如何监听用户的刷新操作

只监听用户用F5刷新
检测F5的keypress keydown等事件，检测是否被摁下

Ext.get(document).on('keydown',function(e){
		var iframeSrc = window.location.href;
		if(e.keyCode == 116){
	        e.preventDefault(); //阻止默认刷新
	        window.location.href = iframeSrc;
		}
	});

参考：https://segmentfault.com/q/1010000004411039

    http://www.open-open.com/lib/view/open1418548024667.html