设置间距
let space = UIBarButtonItem.init(barButtonSystemItem: .fixedSpace, target: nil, action: nil)
space.width = 20
添加间距到item
navigationItem.rightBarButtonItems = [space,OtherItem]
背景颜色设置
navigationController?.navigationBar.barTintColor = .red
navigationController?.navigationBar.barStyle = .blackTranslucent
Item颜色及中间title颜色
navigationController?.navigationBar.tintColor = .white
navigationController?.navigationBar.titleTextAttributes = [NSForegroundColorAttributeName: .red]
