不需要委派

你可以从UITextField为“Primary action triggers”创建一个动作出口，并在传入的sender参数上辞职第一响应者:

@IBAction func done(_ sender: UITextField) {
    sender.resignFirstResponder()
}

超级简单。

(感谢斯科特·史密斯60秒的视频，让我知道了这一点:https://youtu.be/v6GrnVQy7iA)

override func viewDidLoad() {
    super.viewDidLoad()

    let tap = UITapGestureRecognizer(target: self, action: #selector(handleScreenTap(sender:)))
    self.view.addGestureRecognizer(tap)}

然后用这个函数

func handleScreenTap(sender: UITapGestureRecognizer) {
    self.view.endEditing(true)
}

为了获得自动键盘撤销，我将以下代码放在自定义文本字段类的一个方法中:

textField.addTarget(nil, action:"firstResponderAction:", forControlEvents:.EditingDidEndOnExit)

替换你的出口名称为textField。

当用户点击文本键盘上的Done按钮时，将生成Did End on Exit事件;那时，我们需要告诉文本字段放弃控制，这样键盘就会消失。为了做到这一点，我们需要向控制器类添加一个动作方法。 选择ViewController.swift添加以下动作方法:

@IBAction func textFieldDoneEditing(sender: UITextField) {
sender.resignFirstResponder()}

选择主要。项目导航器中的故事板，并调出连接检查器。从Did End On Exit旁边的圆圈拖动到故事板中的黄色视图控制器图标，然后松开。将出现一个小弹出菜单，其中包含我们刚刚添加的单个操作的名称。单击textFieldDoneEditing动作来选择它，就是这样。

所有在一个隐藏键盘和移动键盘打开视图:Swift 5

override func viewDidLoad() {
    super.viewDidLoad()
    let tap = UITapGestureRecognizer(target: self, action: #selector(taped))
    view.addGestureRecognizer(tap)
    NotificationCenter.default.addObserver(self, selector: #selector(KeyboardWillShow), name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(KeyboardWillHide), name: UIResponder.keyboardWillHideNotification, object: nil)
}


   override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(true)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillShowNotification, object: nil)
    NotificationCenter.default.removeObserver(self, name: UIResponder.keyboardWillHideNotification, object: nil)
}
 @objc func taped(){
    
    self.view.endEditing(true)
    
}

@objc func KeyboardWillShow(sender: NSNotification){
    
    let keyboardSize : CGSize = ((sender.userInfo?[UIResponder.keyboardFrameEndUserInfoKey] as? NSValue)?.cgRectValue.size)!
    if self.view.frame.origin.y == 0{
        self.view.frame.origin.y -= keyboardSize.height
    }
    
    
}

@objc func KeyboardWillHide(sender : NSNotification){
    
    let keyboardSize : CGSize = ((sender.userInfo?[UIResponder.keyboardFrameBeginUserInfoKey] as? NSValue)?.cgRectValue.size)!
    if self.view.frame.origin.y != 0{
        self.view.frame.origin.y += keyboardSize.height
    }
    
}


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

Add UITextFieldDelegate to the class declaration: class ViewController: UIViewController, UITextFieldDelegate Connect the textfield or write it programmatically @IBOutlet weak var userText: UITextField! set your view controller as the text fields delegate in view did load: override func viewDidLoad() { super.viewDidLoad() self.userText.delegate = self } Add the following function func textFieldShouldReturn(userText: UITextField!) -> Bool { userText.resignFirstResponder() return true; } with all this your keyboard will begin to dismiss by touching outside the textfield aswell as by pressing return key.