这里有一个简单的方法:

let endEditingTapGesture = UITapGestureRecognizer(target: view, action: #selector(UIView.endEditing(_:)))
endEditingTapGesture.cancelsTouchesInView = false
view.addGestureRecognizer(endEditingTapGesture)

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
    }
}

如何解散键盘时，你点击任何地方关闭它

 //Setup dismiss keyboard gesture
 let tap = UITapGestureRecognizer(target: self, action: #selector(UIInputViewController.dismissKeyboard))

     view.addGestureRecognizer(tap)
 }
 //Calling this function when the tapped
 @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)
    }
}

添加这个扩展到你的ViewController:

  extension UIViewController {
// Ends editing view when touches to view 
  open override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    super.touchesBegan(touches, with: event)
    self.view.endEditing(true)
  }
}

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)
}