Swift5-swift修改navigationbarItem按

1.设置右侧item距离屏幕右边缘的距离

• 其中self.setBtn是自定义button

let setBtnItem: UIBarButtonItem = UIBarButtonItem.init(customView: self.setBtn)
let negativeSpacer: UIBarButtonItem = UIBarButtonItem.init(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
negativeSpacer.width = 20
self.navigationItem.rightBarButtonItems = [UIBarButtonItem](arrayLiteral: negativeSpacer, setBtnItem)

2.设置左侧item距离屏幕左边缘的距离

let setBtnItem: UIBarButtonItem = UIBarButtonItem.init(customView: self.setBtn)
let negativeSpacer: UIBarButtonItem = UIBarButtonItem.init(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
negativeSpacer.width = 100
self.navigationItem.leftBarButtonItems = [UIBarButtonItem](arrayLiteral: negativeSpacer, setBtnItem)

参考

修改navigationbar右侧按钮离屏幕边缘位置
iOS 解决导航栏左右 BarButtonItem偏移位置的问题