我更喜欢这样一句话:

view.addGestureRecognizer(UITapGestureRecognizer(target: self, action: "dismissKeyboardFromView:"))

只要把它放在override viewDidLoad函数中，不管你想让它发生在哪个子类UIViewController中，然后把下面的代码放在你的项目中的一个新的空文件中，名为“UIViewController+dismissKeyboard.swift”:

import UIKit

extension UIViewController {
    // This function is called when the tap is recognized
    func dismissKeyboardFromView(sender: UITapGestureRecognizer?) {
        let view = sender?.view
        view?.endEditing(true)
    }
}

//Simple exercise to demonstrate, assuming the view controller has a //Textfield, Button and a Label. And that the label should display the //userinputs when button clicked. And if you want the keyboard to disappear //when clicken anywhere on the screen + upon clicking Return key in the //keyboard. Dont forget to add "UITextFieldDelegate" and 
//"self.userInput.delegate = self" as below

import UIKit

class ViewController: UIViewController,UITextFieldDelegate {

    @IBOutlet weak var userInput: UITextField!
    @IBAction func transferBtn(sender: AnyObject) {
                display.text = userInput.text

    }
    @IBOutlet weak var display: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

//This is important for the textFieldShouldReturn function, conforming to textfieldDelegate and setting it to self
        self.userInput.delegate = self
    }

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

//This is for the keyboard to GO AWAYY !! when user clicks anywhere on the view
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.view.endEditing(true)
    }


//This is for the keyboard to GO AWAYY !! when user clicks "Return" key  on the keyboard

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

}

如果你有其他视图也应该接收触摸，你必须设置 cancelsTouchesInView = false

是这样的:

let elsewhereTap = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
    elsewhereTap.cancelsTouchesInView = false
    self.view.addGestureRecognizer(elsewhereTap)

对于Swift 3来说，这非常简单

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

如果你想隐藏键盘按回车键

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

但在第二种情况下，你还需要通过委托从所有文本字段的ViewController在主。故事板

Swift 4工作

创建扩展如下所示，并在你的基本视图控制器中调用hideKeyboardWhenTappedAround()。

//
//  UIViewController+Extension.swift
//  Project Name
//
//  Created by ABC on 2/3/18.
//  Copyright © 2018 ABC. All rights reserved.
//

import UIKit

extension UIViewController {
    func hideKeyboardWhenTappedAround() {
        let tapGesture = UITapGestureRecognizer(target: self, 
                         action: #selector(hideKeyboard))
        view.addGestureRecognizer(tapGesture)
    }

    @objc func hideKeyboard() {
        view.endEditing(true)
    }
}

最重要的是调用Base视图控制器这样就不需要在所有视图控制器中调用所有时间。

另一种可能是在你可能需要触摸的所有视图下面添加一个没有内容的大按钮。 给它一个名为:

@IBAction func dismissKeyboardButton(sender: AnyObject) {
    view.endEditing(true)
}

对我来说，手势识别器的问题是，它也捕捉了我想通过tableViewCells接收的所有触摸。