如何在iOS Swift的UIView中的左右和底部設置陰影？

Question

我想在左側，右側和底部看到陰影。 但是Swift 3陰影偏移僅提供高度或寬度。 我發現類似的答案，請參見下面的鏈接，它顯示陰影左上右陰影。 我要左右左右。

1. 看到鏈接有點相似的答案

Answer 1

這幾乎與提供的鏈接相同，只是更改BezierPath 。

let block1 = UIView(frame: CGRect.init(x: 50, y: 50, width: 300, height: 300))
block1.backgroundColor = UIColor.red

block1.layer.masksToBounds = false
block1.layer.shadowOffset = CGSize(width: 0.0, height: 0.0)
block1.layer.shadowRadius = 5.0
block1.layer.shadowOpacity = 0.7

let path = UIBezierPath()
path.move(to: CGPoint(x: 0.0, y: 0.0))
// Move to center between two top points instead of bottom
path.addLine(to: CGPoint(x: block1.frame.size.width/2.0, y: block1.frame.size.height/2.0))
path.addLine(to: CGPoint(x: block1.frame.size.width, y: 0.0))
path.addLine(to: CGPoint(x: block1.frame.size.width, y: block1.frame.size.height))
path.addLine(to: CGPoint(x: 0.0, y: block1.frame.size.height))
path.close()
block1.layer.shadowPath = path.cgPath