To setup an off-canvas menu I have to set the body to "overflow:hidden" to remove scrolling from the body and add it back in to a container around the content with "overflow-y:scroll". When I do this it seems to slow the scrolling on mobile specifically iOS devices.
Is there some sort of performance issue with moving the scrollbar from the body?
Rather than a performance issue this is likely that your not seeing 'Momentum' scrolling on your iOS device
This can be solved by adding '-webkit-overflow-scrolling:touch' to your scrolling element i.e:
.scrolling-content {
overflow-y: scroll;
-webkit-overflow-scrolling: touch;
height:100%; /*A value other than height:auto needs to be set*/
}
By default iOS devices use 'momentum' scrolling on the body but adding 'overflow-y:scroll' to an element does Not set a element to 'momentum' scrolling by default
See https://developer.mozilla.org/en-US/docs/Web/CSS/-webkit-overflow-scrolling for more info
Note: there's a number of Gotcha/Bugs with using -webkit-overflow-scrolling: touch on certain browsers
来源：https://stackoverflow.com/questions/33601165/scrolling-slow-on-mobile-ios-when-using-overflowscroll