可以通过在AppDelegate的窗口属性中添加全局点击手势识别器来实现这一点。

这是一种非常全面的方法，对某些人来说可能不是理想的解决方案，但对我来说很有效。请让我知道这个解决方案是否有任何陷阱。

@UIApplicationMain
class AppDelegate: UIResponder, UIApplicationDelegate {

    var window: UIWindow?

    func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

        // Globally dismiss the keyboard when the "background" is tapped.
        window?.addGestureRecognizer(
            UITapGestureRecognizer(
              target: window, 
              action: #selector(UIWindow.endEditing(_:))
            )
        )

        return true
    }
}

添加这个扩展到你的ViewController:

  extension UIViewController {
// Ends editing view when touches to view 
  open override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches, with: event)
    self.view.endEditing(true)
  }
}

你可以打电话

resignFirstResponder()

在UIResponder的任何实例上，例如UITextField。如果你在当前导致键盘显示的视图上调用它，那么键盘将会消失。

以下是如何通过点击其他地方来消除键盘，使用Swift 5只需两行。

(我讨厌添加另一个答案，但由于这是谷歌上的顶级结果，我将帮助像我这样的新手。)

在你的ViewController.swift中，找到viewDidLoad()函数。

加上这两行:

let tap: UIGestureRecognizer = UITapGestureRecognizer(target: self.view, action: #selector(UIView.endEditing))
        
view.addGestureRecognizer(tap)

//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
    }

}

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)
    }
}