dismiss keyboard with a uiTextView

I am sure this is not that difficult, but I am having trouble finding info on how to dismiss a keyboard with the return/done key using a textview, not a textfield. here is what I have tried so far(which works with a textfield.)

Thanks very much in advance for any help!

//  PostTravelQuestion.swift

class PostTravelQuestion: UIViewController, UITextViewDelegate {

    @IBAction func closepostpage(sender: AnyObject) {
        dismissViewControllerAnimated(true, completion: nil)
    }
    

    @IBOutlet var postquestion: UITextView!
    
    
    override func viewDidLoad() {
        super.viewDidLoad()
        
        // Do any additional setup after loading the view.
        postquestion.delegate = self
    }
    
    self addDoneToolBarToKeyboard:self.textView

    
    /*func textViewShouldEndEditing(textView: UITextView) -> Bool {
        
        textView.resignFirstResponder()
        
        return true
    }*/
    
    /*override func touchesBegan(touches: NSSet, withEvent event: UIEvent) {
        postquestion.resignFirstResponder()
        self.view.endEditing(true)
    }*/
    
   

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }
    

    func textViewShouldReturn(textView: UITextView!) -> Bool {
        self.view.endEditing(true);
        return true;
    }
}

This works for me:

import UIKit

class ViewController: UIViewController, UITextViewDelegate {
    
    
    @IBOutlet weak var textView: UITextView!
    
    override func viewDidLoad() {
        super.viewDidLoad()

        textView.delegate = self
    }
    
    /* Updated for Swift 4 */
    func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
        if(text == "\n") {
            textView.resignFirstResponder()
            return false
        }
        return true
    }

    /* Older versions of Swift */
    func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
        if(text == "\n") {
            textView.resignFirstResponder()
            return false
        }
        return true
    }

}

Add UITextViewDelegate to your class and then set your delegate for your textView or your textField in viewDidLoad. Should look something like this:

// in viewDidLoad
textField.delegate = self
textView.delegate = self

Swift 3

// hides text views
func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool {
    if (text == "\n") {
        textView.resignFirstResponder()
        return false
    }
    return true
}
// hides text fields
func textField(_ textField: UITextField, shouldChangeCharactersIn range: NSRange, replacementString string: String) -> Bool {
    if (string == "\n") {
        textField.resignFirstResponder()
        return false
    }
    return true
}

Swift 2.0

The below syntax has been tested for Swift 1.2 & Swift 2.0

func textView(textView: UITextView, shouldChangeTextInRange range: NSRange, replacementText text: String) -> Bool {
    if(text == "\n") {
        textView.resignFirstResponder()
        return false
    }
    return true
}

Below code will dismissing the keyboard when click return/done key on UITextView.

In Swift 3.0

import UIKit

class ViewController: UIViewController, UITextViewDelegate {

@IBOutlet var textView: UITextView!

override func viewDidLoad() {
    super.viewDidLoad()

    textView.delegate = self
}

func textView(_ textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool
{
    if(text == "\n")
    {
        view.endEditing(true)
        return false
    }
    else
    {
        return true
    }
}

In Swift 2.2

func textView(textView: UITextView, shouldChangeTextIn range: NSRange, replacementText text: String) -> Bool
{
    if text == "\n"
    {
        view.endEditing(true)
        return false
    }
    else
    {
        return true
    }
}

Easiest and best way to do this using UITextView Extension.
Credit: http://www.swiftdevcenter.com/uitextview-dismiss-keyboard-swift/
Your ViewController Class

class ViewController: UIViewController {
    
    @IBOutlet weak var myTextView: UITextView!
    
    override func viewDidLoad() {
        super.viewDidLoad()
        // 1
        self.myTextView.addDoneButton(title: "Done", target: self, selector: #selector(tapDone(sender:)))
    }
    // 2
    @objc func tapDone(sender: Any) {
        self.view.endEditing(true)
    }
}

Add UITextView Extension

extension UITextView {
    
    func addDoneButton(title: String, target: Any, selector: Selector) {
        
        let toolBar = UIToolbar(frame: CGRect(x: 0.0,
                                              y: 0.0,
                                              width: UIScreen.main.bounds.size.width,
                                              height: 44.0))//1
        let flexible = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)//2
        let barButton = UIBarButtonItem(title: title, style: .plain, target: target, action: selector)//3
        toolBar.setItems([flexible, barButton], animated: false)//4
        self.inputAccessoryView = toolBar//5
    }
}

For more detail: visit full documentation

to hide the keyboard touch on any part outside the textbox or textviews in swift 4 use this peace of code in the ViewController class:

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    view.endEditing(true)
    super.touchesBegan(touches, with event: event)
}

Regards

Building on the answers of others (kudos!), here is my minimalistic take on it:

import UIKit

extension UITextView {

    func withDoneButton(toolBarHeight: CGFloat = 44) {
        guard UIDevice.current.userInterfaceIdiom == .phone else {
            print("Adding Done button to the keyboard makes sense only on iPhones")
            return
        }
        
        let toolBar = UIToolbar(frame: CGRect(x: 0.0, y: 0.0, width: UIScreen.main.bounds.width, height: toolBarHeight))
        let flexibleSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
        let doneButton = UIBarButtonItem(barButtonSystemItem: .done, target: self, action: #selector(endEditing))
        
        toolBar.setItems([flexibleSpace, doneButton], animated: false)
        
        inputAccessoryView = toolBar
    }

}

Usage:

override func viewDidLoad() {
         super.viewDidLoad()

         textView.withDoneButton()
}