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
    }
}

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()
}

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

  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)
  }
}

对于Swift3

在viewDidLoad中注册一个事件识别器

let tap = UITapGestureRecognizer(target: self, action: #selector(hideKeyBoard))

然后我们需要在相同的viewDidLoad中添加手势到视图中。

self.view.addGestureRecognizer(tap)

然后我们需要初始化注册的方法

func hideKeyBoard(sender: UITapGestureRecognizer? = nil){
    view.endEditing(true)
}

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)