从 TextField 中移除子层

Question

我需要两个函数，一个添加底部边框，一个删除底部边框。我怎样才能删除我创建的这个寄宿生？

extension UITextField {
    func addBottomBorder(){
        let bottomLine = CALayer()
        bottomLine.frame = CGRect.init(x: 0, y: self.frame.size.height - 1, width: self.frame.size.width, height: 1)
        bottomLine.backgroundColor = UIColor.white.cgColor
        self.borderStyle = UITextBorderStyle.none
        self.layer.addSublayer(bottomLine)
    }
    func removeBottomBorder(){        
    }
}

Answer 1

您可以尝试使用 .removeFromSuperlayer() 删除图层，因此保留对它的引用

extension UITextField {

    func addBottomBorder(){

         let bottomLine = CALayer()
         bottomLine.frame = CGRect.init(x: 0, y: self.frame.size.height - 1, width: self.frame.size.width, height: 1)
         bottomLine.backgroundColor = UIColor.red.cgColor
         self.layer.addSublayer(bottomLine)


     }
     func removeBottomBorder() {
         self.layer.sublayers?.first?.removeFromSuperlayer()
     }
}

为了安全起见，您可以添加其他子层

extension UITextField {

  func addBottomBorder(){
     let bottomLine = UIView()
     bottomLine.tag = 23
     bottomLine.frame = CGRect.init(x: 0, y: self.frame.size.height - 1, width: self.frame.size.width, height: 1)
     bottomLine.backgroundColor = UIColor.red
     self.addSubview(bottomLine)
  }
  func removeBottomBorder() {
    self.subviews.forEach {
        if [=11=].tag == 23 {
            [=11=].removeFromSuperview()
        }
    }
  }
}

从 TextField 中移除子层

Remove a sublayer from TextField

calayer

uitextfield

ios

uitextborderstyle

swift