fileprivate let lxfFlag: Int = 666extension UITabBar { // MARK:- 顯示小紅點 func showBadgOn(index itemIndex: Int, tabbarItemNums: CGFloat = 4.0) {  // 移除之前的小紅點  self.removeBadgeOn(index: itemIndex)  // 創建小紅點  let bageView = UIView()  bageView.tag = itemIndex + lxfFlag  bageView.layer.cornerRadius = 5  bageView.backgroundColor = UIColor.red  let tabFrame = self.frame  // 確定小紅點的位置  let percentX: CGFloat = (CGFloat(itemIndex) + 0.59) / tabbarItemNums  let x: CGFloat = CGFloat(ceilf(Float(percentX * tabFrame.size.width)))  let y: CGFloat = CGFloat(ceilf(Float(0.115 * tabFrame.size.height)))  bageView.frame = CGRect(x: x, y: y, width: 10, height: 10)  self.addSubview(bageView) } // MARK:- 隱藏小紅點 func hideBadg(on itemIndex: Int) {  // 移除小紅點  self.removeBadgeOn(index: itemIndex) } // MARK:- 移除小紅點 fileprivate func removeBadgeOn(index itemIndex: Int) {  // 按照tag值進行移除  _ = subviews.map {   if $0.tag == itemIndex + lxfFlag {    $0.removeFromSuperview()   }  } }}

// 默認4個tabbarItemself.tabBarController?.tabBar.showBadgOn(index: 2)// 如果不是則用這個方法// self.tabBarController?.tabBar.showBadgOn(index: Int, tabbarItemNums: CGFloat)