解决ios10以上H5页面手势、双击缩放问题

html:<meta content="width=device-width, initial-scale=1.0, maximum-scale=1.0, user-scalable=0;" name="viewport" /> 　　
js:
    window.onload = function() {
        // 阻止双击放大
        var lastTouchEnd = 0;
        document.addEventListener('touchstart', function(event) {
            if (event.touches.length > 1) {
                event.preventDefault();
            }
        });
        document.addEventListener('touchend', function(event) {
            var now = (new Date()).getTime();
            if (now - lastTouchEnd <= 300) {
                event.preventDefault();
            }
            lastTouchEnd = now;
        }, false);

        // 阻止双指放大
        document.addEventListener('gesturestart', function(event) {
            event.preventDefault();
        });
    };