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
    }
}

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

作为一个新手程序员，当人们给出更熟练和不必要的回答时，可能会感到困惑……你不需要做上面所示的任何复杂的事情!

这是最简单的选择……在这种情况下，你的键盘出现在响应文本字段-在你的触摸屏函数中，只需添加resignFirstResponder函数。如下所示-键盘将关闭，因为First Responder被释放(退出Responder链)…

override func touchesBegan(_: Set<UITouch>, with: UIEvent?){
    MyTextField.resignFirstResponder()
}

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。

您还可以添加一个点击手势识别器来重新使用键盘。: D

override func viewDidLoad() {
    super.viewDidLoad()
    // Do any additional setup after loading the view, typically from a nib.

    let recognizer = UITapGestureRecognizer(target: self, action: Selector("handleTap:"))
    backgroundView.addGestureRecognizer(recognizer)
}
    func handleTap(recognizer: UITapGestureRecognizer) {
    textField.resignFirstResponder()
    textFieldtwo.resignFirstResponder()
    textFieldthree.resignFirstResponder()

    println("tappped")
}

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)