我建议从RSC初始化类:

import Foundation
import UIKit

// Don't forget the delegate!
class ViewController: UIViewController, UITextFieldDelegate {

required init(coder aDecoder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
}

@IBOutlet var myTextField : UITextField?

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    self.myTextField.delegate = self;
}

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

func textFieldShouldReturn(textField: UITextField!) -> Bool {
    self.view.endEditing(true);
    return false;
}

}

另一种主要使用故事板并轻松允许你拥有多个文本字段的方法是:

@IBAction func resignKeyboard(sender: AnyObject) {
    sender.resignFirstResponder()
}

将视图控制器的所有文本字段连接到每个字段的Did End on Exit事件上的那个动作。

我讨厌给每个UIViewController添加相同的函数。 通过扩展UIViewController来支持UITextFieldDelegate，你可以提供一个默认行为“返回按下”。

extension UIViewController: UITextFieldDelegate{
    public func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true;
    }
}

当你创建新的UIViewController和UITextField时，你所要做的就是在你的UIViewController中写一行代码。

override func viewDidLoad() {
    super.viewDidLoad()
    textField.delegate = self
}

你甚至可以通过在Main.storyboard中钩子委托来省略这一行代码。(使用“ctrl”从UITextField拖动到UIViewController)

它的返回true部分只告诉文本字段是否允许返回。 你必须手动告诉文本字段解散键盘(或者它的第一个响应器是什么)，这是通过resignFirstResponder()来完成的，如下所示:

// Called on 'Return' pressed. Return false to ignore.

func textFieldShouldReturn(_ textField: UITextField) -> Bool { 
    textField.resignFirstResponder()
    return true
}

在你正在使用的视图控制器中:

//suppose you are using the textfield label as this

@IBOutlet weak var emailLabel: UITextField!
@IBOutlet weak var passwordLabel: UITextField!

//then your viewdidload should have the code like this
override func viewDidLoad() {
        super.viewDidLoad()

        self.emailLabel.delegate = self
        self.passwordLabel.delegate = self

    }

//then you should implement the func named textFieldShouldReturn
 func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        textField.resignFirstResponder()
        return true
    }

// -- then, further if you want to close the keyboard when pressed somewhere else on the screen you can implement the following method too:

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

您可以使用以下函数使应用程序解除键盘

func textFieldShouldReturn(_ textField: UITextField) -> Bool {
    self.view.endEditing(true)
    return false
}

下面是一个完整的例子来更好地说明这一点:

//
//  ViewController.swift
//
//

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var myTextField : UITextField

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        self.myTextField.delegate = self
    }

    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        self.view.endEditing(true)
        return false
    }
}

代码来源:http://www.snip2code.com/Snippet/85930/swift-delegate-sample