关于IOS中实现textfield圆角的问题

import UIKit

let borderColor = UIColor.lightGrayColor()
let tblFrame = CGRect(x: 0, y: 0, width: 200, height: 80)

let tblView = UITableView(frame: tblFrame)
tblView.rowHeight = 41
tblView.separatorColor = borderColor
tblView.separatorInset = UIEdgeInsets(top: 0, left: 0, bottom: 0, right: 0)

let bgView = UIView(frame: tblFrame)
bgView.layer.borderColor = borderColor.CGColor
bgView.layer.borderWidth = 1
bgView.layer.cornerRadius = 10
tblView.backgroundView = bgView

tblView.addSubview(UITextField())
tblView.addSubview(UITextField())