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

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)
    }
}

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 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

斯威夫特3: 关闭键盘的最简单方法:

  //Dismiss keyboard method
    func keyboardDismiss() {
        textField.resignFirstResponder()
    }

    //ADD Gesture Recignizer to Dismiss keyboard then view tapped
    @IBAction func viewTapped(_ sender: AnyObject) {
        keyboardDismiss()
    }

    //Dismiss keyboard using Return Key (Done) Button
    //Do not forgot to add protocol UITextFieldDelegate 
    func textFieldShouldReturn(_ textField: UITextField) -> Bool {
        keyboardDismiss()

        return true
    }

我没有看到它被提到过，但是NotificationCenter可以告诉你键盘何时打开和关闭。例如，如果你想改变cancelsTouchesInView或一起删除手势识别器，这可以被使用。

例子:

var dismissKeyboardGestureRecognizer = UITapGestureRecognizer()

override func viewDidLoad() {
    super.viewDidLoad()

    //Setup dismiss keyboard gesture
    self.dismissKeyboardGestureRecognizer = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))

    //Add Notifications
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardDidShow), name:UIResponder.keyboardDidShowNotification, object: nil)
    NotificationCenter.default.addObserver(self, selector: #selector(keyboardDidHide), name:UIResponder.keyboardDidHideNotification, object: nil)
}

@objc func keyboardDidShow() {
    dismissKeyboardGestureRecognizer.cancelsTouchesInView = true
    view.addGestureRecognizer(dismissKeyboardGestureRecognizer)
}

@objc func keyboardDidHide() {
    dismissKeyboardGestureRecognizer.cancelsTouchesInView = false
    view.removeGestureRecognizer(dismissKeyboardGestureRecognizer)
}

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