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)
}

当视图中有多个文本字段时

为了遵循@modocache的建议避免调用view. enditing()，您可以跟踪成为第一响应器的文本字段，但这很混乱且容易出错。

另一种方法是在视图控制器中的所有文本字段上调用resignFirstResponder()。下面是一个创建所有文本字段集合的示例(在我的情况下，验证代码无论如何都需要):

@IBOutlet weak var firstName: UITextField!
@IBOutlet weak var lastName: UITextField!
@IBOutlet weak var email: UITextField!

var allTextFields: Array<UITextField>!  // Forced unwrapping so it must be initialized in viewDidLoad
override func viewDidLoad()
{
    super.viewDidLoad()
    self.allTextFields = [self.firstName, self.lastName, self.email]
}

有了可用的集合，就可以简单地遍历所有这些集合:

private func dismissKeyboard()
{
    for textField in allTextFields
    {
        textField.resignFirstResponder()
    }
}

所以现在你可以在你的手势识别器(或任何适合你的地方)中调用遣散键盘()。缺点是在添加或删除字段时必须维护UITextFields列表。

欢迎评论。如果在不是第一响应者的控件上调用resignFirstResponder()有问题，或者如果有一种简单且保证无bug的方法来跟踪当前的第一响应者，我很乐意听到它!

在Swift 4中，添加@objc:

在viewDidLoad中:

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

功能:

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

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)
    }
}

  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)
  }
}

因为我编辑的@King-Wizard的回答被拒绝了，所以发布了一个新的答案。

让你的类成为UITextField的委托并重写touchesBegan。

斯威夫特4

import UIKit

class ViewController: UIViewController, UITextFieldDelegate {

    @IBOutlet var textField: UITextField!

    override func viewDidLoad() {
        super.viewDidLoad()
        textField.delegate = self
    }

    //Called when 'return' key is pressed. Return false to keep the keyboard visible.
    func textFieldShouldReturn(textField: UITextField) -> Bool {
        return true
    }

    // Called when the user clicks on the view (outside of UITextField).
    override func touchesBegan(touches: Set<UITouch>, with event: UIEvent?) {
        self.view.endEditing(true)
    }

}