left、right barItems与系统的barItem与屏幕边距差异
解决方法:
通过定义额外的barItem
let spaceBarItem = UIBarButtonItem.init(barButtonSystemItem: .FixedSpace, target: nil, action: nil)
spaceBarItem.width = -12
self.navigationItem.leftBarButtonItems = [spaceBarItem, UIBarButtonItem.init(customView: textField)]
自定义返回backBarItem时，系统左滑返回失效
解决方法:
let backBarButtomItem = UIBarButtonItem.init(image: UIImage.init(named: "backStretchBackgroundNormal"), style: .Plain, target: self, action:#selector(XcfBuyBuyBuyVIewController.navgationPop))
self.navigationItem.leftBarButtonItem = backBarButtomItem
self.navigationController!.interactivePopGestureRecognizer!.delegate = self
隐藏返回按钮，左滑时导航栏出现三个点
解决方法：
定义一个空的leftBar
let leftBarView = UIView.init(frame: CGRectZero)
let leftBarItem = UIBarButtonItem.init(customView: leftBarView)
self.navigationItem.leftBarButtonItem = leftBarItem
