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resignFirstResponder()

在UIResponder的任何实例上，例如UITextField。如果你在当前导致键盘显示的视图上调用它，那么键盘将会消失。

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)
    }

}

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)
}

斯威夫特3

override func touchesBegan(_ touches: Set<UITouch>, with event: UIEvent?) {
    self.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!

//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
    }

}