viewDidLoad()方法中只有一行代码:

view.addGestureRecognizer(UITapGestureRecognizer(target: view, action: #selector(UIView.endEditing(_:))))

Swift 5只要两行就够了。添加到你的viewDidLoad应该工作。

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

如果你的点击手势阻止了一些其他的触摸，那么添加这一行:

tapGesture.cancelsTouchesInView = false

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

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)
  }
}

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。

  import UIKit

  class ItemViewController: UIViewController, UITextFieldDelegate {

  @IBOutlet weak var nameTextField: UITextField!

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

    // Called when 'return' key pressed. return NO to ignore.

    func textFieldShouldReturn(textField: UITextField) -> Bool {

            textField.resignFirstResponder()
             return true
     }

 // Called when the user click on the view (outside the UITextField).

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