阻止IOS10+ 缩放问题

mata:

<meta name="viewport" content="width=device-width,initial-scale=1.0,maximum-scale=1.0,minimum-scale=1.0,user-scalable=no">

javascript:

/*阻止缩放*/
    	window.onload=function () {
        document.addEventListener('touchstart',function (event) {
            if(event.touches.length>1){
                event.preventDefault();
            }
        })
        document.addEventListener(
			    "touchmove",
			    function(event) {
			    	event = event.originalEvent || event;
			    	 if (event.touches.length > 1) {
					        event.preventDefault();
					    }
			    },
			    { passive: false }
			);
        var lastTouchEnd=0;
        document.addEventListener('touchend',function (event) {
            var now=(new Date()).getTime();
            if(now-lastTouchEnd<=300){
                event.preventDefault();
            }
            lastTouchEnd=now;
        },false)
        document.addEventListener('gesturestart', function (event) {
		      event.preventDefault();
		    });  
    }