//Simple exercise to demonstrate, assuming the view controller has a //Textfield, Button and a Label. And that the label should display the //userinputs when button clicked. And if you want the keyboard to disappear //when clicken anywhere on the screen + upon clicking Return key in the //keyboard. Dont forget to add "UITextFieldDelegate" and 
//"self.userInput.delegate = self" as below

import UIKit

class ViewController: UIViewController,UITextFieldDelegate {

    @IBOutlet weak var userInput: UITextField!
    @IBAction func transferBtn(sender: AnyObject) {
                display.text = userInput.text

    }
    @IBOutlet weak var display: UILabel!

    override func viewDidLoad() {
        super.viewDidLoad()

//This is important for the textFieldShouldReturn function, conforming to textfieldDelegate and setting it to self
        self.userInput.delegate = self
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

//This is for the keyboard to GO AWAYY !! when user clicks anywhere on the view
    override func touchesBegan(touches: Set<UITouch>, withEvent event: UIEvent?) {
        self.view.endEditing(true)
    }


//This is for the keyboard to GO AWAYY !! when user clicks "Return" key  on the keyboard

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

}

我发现最好的解决方案包括来自@Esqarrouth的接受答案，并进行了一些调整:

extension UIViewController {
    func hideKeyboardWhenTappedAround() {
        let tap: UITapGestureRecognizer = UITapGestureRecognizer(target: self, action: "dismissKeyboardView")
        tap.cancelsTouchesInView = false
        view.addGestureRecognizer(tap)
    }

    func dismissKeyboardView() {
        view.endEditing(true)
    }
}

电话响了。cancelsTouchesInView = false是关键的:它确保UITapGestureRecognizer不会阻止视图上的其他元素接收用户交互。

方法解雇键盘()被更改为稍微不那么优雅的解雇keyboardview()。这是因为在我的项目相当旧的代码库中，有很多次已经使用了dismissKeyboard()(我想这并不少见)，导致编译器问题。

然后，如上所述，这个行为可以在各个视图控制器中启用:

override func viewDidLoad() {
    super.viewDidLoad()
    self.hideKeyboardWhenTappedAround() 
}

viewDidLoad()方法中只有一行代码:

view.addGestureRecognizer(UITapGestureRecognizer(target: view, action: #selector(UIView.endEditing(_:))))

如果你有其他视图也应该接收触摸，你必须设置 cancelsTouchesInView = false

是这样的:

let elsewhereTap = UITapGestureRecognizer(target: self, action: #selector(dismissKeyboard))
    elsewhereTap.cancelsTouchesInView = false
    self.view.addGestureRecognizer(elsewhereTap)

这一行代码辞去了UIView中所有UITextField的键盘

self.view.endEditing(true)

如果你使用滚动视图，它会简单得多。

只需在故事板中交互式地选择解散。