设置阴影的颜色、透明度、偏移量和半径。例如：
myView.layer.shadowColor = UIColor.black.cgColor
myView.layer.shadowOpacity = 0.5
myView.layer.shadowOffset = CGSize(width: 0, height: 3)
myView.layer.shadowRadius = 5
设置View的背景色和圆角半径。例如：
myView.backgroundColor = UIColor.white
myView.layer.cornerRadius = 10
设置边框的颜色、宽度和圆角半径。例如：
myView.layer.borderColor = UIColor.blue.cgColor
myView.layer.borderWidth = 2
myView.layer.cornerRadius = 10
