IOS禁止侧边滑动调出快捷菜单

有时候你的App需要控制从状态栏下拉或者底部栏上滑，这个会跟系统的下拉通知中心手势和上滑控制中心手势冲突。
如果你要优先自己处理手势可以将系统手势延迟。

@interface UIViewController (UIScreenEdgesDeferringSystemGestures)

// Override to return a child view controller or nil. If non-nil, that view controller’s screen edges deferring system gestures will be used. If nil, self is used. Whenever the return value changes, -setNeedsScreenEdgesDeferringSystemGesturesUpdate should be called.

• (nullable UIViewController *)childViewControllerForScreenEdgesDeferringSystemGestures API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(watchos, tvos);

// Controls the application’s preferred screen edges deferring system gestures when this view controller is shown. Default is UIRectEdgeNone.

• (UIRectEdge)preferredScreenEdgesDeferringSystemGestures API_AVAILABLE(ios(11.0)) API_UNAVAILABLE(watchos, tvos);

// This should be called whenever the return values for the view controller’s screen edges deferring system