ios - 如何为 MDCTextField 添加阴影？

Question

这是我的代码:

@IBOutlet var txtFirstName: MDCTextField!
var txtFirstNameController: MDCTextInputControllerOutlined?
override func viewDidLoad() {
txtFirstNameController = MDCTextInputControllerOutlined(textInput: txtFirstName)
}

我想在文本字段中添加阴影，但我不知道如何使用 MaterialComponents我在这里提到了我测试过的所有方法及其结果:

第一种方式:

class ShadowLayer : MDCTextField{
override class var layerClass: AnyClass {
    return MDCShadowLayer.self
}

var shadowLayer: MDCShadowLayer {
    return self.layer as! MDCShadowLayer
}

func setDefaultElevation() {
    self.shadowLayer.elevation = .cardResting
}
}

第二种方式:

extension MDCTextField {

func elevate(elevation: Double) {
    self.backgroundColor = UIColor.white
    self.layer.masksToBounds = false
    self.layer.shadowColor = UIColor.black.cgColor
    self.layer.shadowOffset = CGSize(width: 0, height: elevation)
    self.layer.shadowRadius = CGFloat(elevation)
    self.layer.shadowOpacity = 1

}
}

选择国家->第一种方式，选择城市->第二种方式

我要的是下图:

Answer 1

尝试设置 self.clipsToBounds = true before 设置 self.layer.masksToBounds = false

您的提升功能应如下所示:

func elevate(elevation: Double) {
    self.backgroundColor = UIColor.white
    self.clipsToBounds = true
    self.layer.masksToBounds = false
    self.layer.shadowColor = UIColor.black.cgColor
    self.layer.shadowOffset = CGSize(width: 0, height: elevation)
    self.layer.shadowRadius = CGFloat(elevation)
    self.layer.shadowOpacity = 1
}