swift3, UIView学习 - textview

import UIKit

class ViewController:UIViewController {

    overridefunc viewDidLoad() {

        super.viewDidLoad()

        let textview = UITextView(frame:CGRect(x: 10,y: 20,width: 300,height: 120))

        textview.layer.borderWidth = 2

        textview.layer.borderColor = UIColor.gray().cgColor

      self.view.addSubview(textview)

    }

}