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

为了扩展Esqarrouth的答案，我总是使用以下方法来解除键盘，特别是如果我正在解除键盘的类没有view属性和/或不是UIView的子类。

UIApplication.shared.keyWindow?.endEditing(true)

并且，为了方便起见，下面是uiapplication类的扩展:

extension UIApplication {

    /// Dismisses the keyboard from the key window of the
    /// shared application instance.
    ///
    /// - Parameters:
    ///     - force: specify `true` to force first responder to resign.
    open class func endEditing(_ force: Bool = false) {
        shared.endEditing(force)
    }

    /// Dismisses the keyboard from the key window of this 
    /// application instance.
    ///
    /// - Parameters:
    ///     - force: specify `true` to force first responder to resign.
    open func endEditing(_ force: Bool = false) {
        keyWindow?.endEditing(force)
    }

}

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

我已经使用IQKeyBoardManagerSwift键盘。它很容易使用。 只需添加pod 'IQKeyboardManagerSwift'

导入IQKeyboardManagerSwift并在AppDelegate中的didFinishLaunchingWithOptions上编写代码。

///add this line 
IQKeyboardManager.shared.shouldResignOnTouchOutside = true
IQKeyboardManager.shared.enable = true

  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)
  }
}

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
    }
}