如何在带有圆角的UITextField上添加阴影？

Question

我想在UITextField圆角上实现阴影，如下图所示：

我的代码如下：

    override func viewDidLoad() {
       super.viewDidLoad()
       textField.layer.cornerRadius =             textField.frame.size.height / 2
       textField.layer.borderWidth = 1.0
       textField.layer.borderColor = UIColor(white: 0.5, alpha: 0.3).cgColor
       textField.layer.shadowOpacity = 1
       textField.layer.shadowRadius = 4.0
       textField.layer.shadowColor = UIColor.black.cgColor
    }

但是，我认为有些东西丢失了...

输出：

提前致谢！

Answer 1

尝试下面的代码在roundRect文本字段上实现阴影效果。

    //Basic texfield Setup 
    textField.borderStyle = .none
    textField.backgroundColor = UIColor.groupTableViewBackground // Use anycolor that give you a 2d look.

    //To apply corner radius
    textField.layer.cornerRadius = textField.frame.size.height / 2

    //To apply border
    textField.layer.borderWidth = 0.25
    textField.layer.borderColor = UIColor.white.cgColor

    //To apply Shadow
    textField.layer.shadowOpacity = 1
    textField.layer.shadowRadius = 3.0
    textField.layer.shadowOffset = CGSize.zero // Use any CGSize
    textField.layer.shadowColor = UIColor.gray.cgColor

    //To apply padding
    let paddingView : UIView = UIView(frame: CGRect(x: 0, y: 0, width: 20, height: textField.frame.height))
    textField.leftView = paddingView
    textField.leftViewMode = UITextFieldViewMode.always

注意：由于某些原因textField.borderStyle = .none，即使在viewWillLayoutSubviews()或中设置代码也无法生效viewDidLayoutSubviews()。因此，我建议您通过storyBoard textfield设置borderStyle Attributes inspector。

真实设备的输出：

要实现投影效果：（就像其他SO帖子一样）

   textField.layer.borderColor = UIColor.black.withAlphaComponent(0.25).cgColor
   textField.layer.shadowOffset = CGSize(width: 0, height: 3)
   textField.layer.shadowColor = UIColor.black.cgColor //Any dark color

输出：