override func viewDidLoad() {
    super.viewDidLoad()
          
    //Looks for single or multiple taps. 
     let tap = UITapGestureRecognizer(target: self, action: #selector(UIInputViewController.dismissKeyboard))

    //Uncomment the line below if you want the tap not not interfere and cancel other interactions.
    //tap.cancelsTouchesInView = false 

    view.addGestureRecognizer(tap)
}

//Calls this function when the tap is recognized.
@objc func dismissKeyboard() {
    //Causes the view (or one of its embedded text fields) to resign the first responder status.
    view.endEditing(true)
}

如果你打算在多个uiviewcontroller中使用这个功能，这里有另一种方法来完成这个任务:

// Put this piece of code anywhere you like
extension UIViewController {
    func hideKeyboardWhenTappedAround() {
        let tap = UITapGestureRecognizer(target: self, action: #selector(UIViewController.dismissKeyboard))
        tap.cancelsTouchesInView = false            
        view.addGestureRecognizer(tap)
    }
    
    @objc func dismissKeyboard() {
        view.endEditing(true)
    }
}

现在在每个UIViewController中，你要做的就是调用这个函数:

override func viewDidLoad() {
    super.viewDidLoad()
    self.hideKeyboardWhenTappedAround() 
}

这个函数是我的repo中包含的标准函数，它包含了很多有用的Swift扩展，比如这个，看看:https://github.com/goktugyil/EZSwiftExtensions

//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)

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。

使用IQKeyboardmanager，将帮助您解决简单.....

/////////////////////////////////////////

[如何禁用键盘..][1].

import UIKit

class ViewController: UIViewController,UITextFieldDelegate {

   @IBOutlet weak var username: UITextField!
   @IBOutlet weak var password: UITextField!

   override func viewDidLoad() {
      super.viewDidLoad() 
      username.delegate = self
      password.delegate = self
      // Do any additional setup after loading the view, typically from a nib.
   }

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

   func textFieldShouldReturn(textField: UITextField!) -> Bool // called when   'return' key pressed. return NO to ignore.
   {
      textField.resignFirstResponder()
      return true;
   }

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

斯威夫特3:

扩展选择器作为参数，能够做额外的东西在解散函数和cancelsTouchesInView，以防止扭曲与触摸的其他元素的视图。

extension UIViewController {
    func hideKeyboardOnTap(_ selector: Selector) {
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: selector)
        tap.cancelsTouchesInView = false
        view.addGestureRecognizer(tap)
    }
}

用法:

override func viewDidLoad() {
    super.viewDidLoad()
    self.hideKeyboardOnTap(#selector(self.dismissKeyboard))
}

func dismissKeyboard() {
    view.endEditing(true)
    // do aditional stuff
}