let pickerView = UIPickerView()
   
 var yearpickerToolbar: UIToolbar?
   
    func createPickerView() {
          
           pickerView.delegate = self
           textfield.inputView = pickerView }
   
   
     func dismissPickerView() {
           let toolBar = UIToolbar()
           toolBar.sizeToFit()
   
           toolBar.isUserInteractionEnabled = true
           textfield.inputAccessoryView = toolBar
           textfield.delegate = self
   
   
   yearpickerToolbar = UIToolbar()
           yearpickerToolbar?.autoresizingMask = .flexibleHeight
   
           //add buttons
           let cancelButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action:#selector(cancelBtnClicked(_:)))
           cancelButton.tintColor = UIColor.blue
           let flexSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
           
           let doneButton = UIBarButtonItem(title: "Done", style: .plain , target: self, action: #selector(self.doneBtnClicked(_ :) ))
           doneButton.tintColor = UIColor.blue
   
           doneButton.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:
   UIColor.black], for: .normal)
           cancelButton.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:
   UIColor.black], for: .normal)
           
           yearpickerToolbar?.items = [cancelButton, flexSpace, doneButton]
           textfield.inputAccessoryView = yearpickerToolbar }
   
   @objc func cancelBtnClicked(_ button: UIBarButtonItem?) {
           self.view.endEditing(true)
           
       }
   
       @objc func doneBtnClicked(_ button: UIBarButtonItem?) {
           self.view.endEditing(true)
       }

最简单的方法是:创建自定义透明按钮并将其放置在左下角，它将具有与UIKeyboardTypeNumberPad中的空白空间相同的CGSize。切换(显示/隐藏)这个按钮在textField成为firstresponder，按钮点击分别。

 let pickerView = UIPickerView()
   
 var yearpickerToolbar: UIToolbar?
   
    func createPickerView() {
          
           pickerView.delegate = self
           textfield.inputView = pickerView }
   
   
     func dismissPickerView() {
           let toolBar = UIToolbar()
           toolBar.sizeToFit()
   
           toolBar.isUserInteractionEnabled = true
           textfield.inputAccessoryView = toolBar
           textfield.delegate = self
   
   
   yearpickerToolbar = UIToolbar()
           yearpickerToolbar?.autoresizingMask = .flexibleHeight
   
           //add buttons
           let cancelButton = UIBarButtonItem(barButtonSystemItem: .cancel, target: self, action:#selector(cancelBtnClicked(_:)))
           cancelButton.tintColor = UIColor.blue
           let flexSpace = UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: nil, action: nil)
           
           let doneButton = UIBarButtonItem(title: "Done", style: .plain , target: self, action: #selector(self.doneBtnClicked(_ :) ))
           doneButton.tintColor = UIColor.blue
   
           doneButton.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:
   UIColor.black], for: .normal)
           cancelButton.setTitleTextAttributes([NSAttributedString.Key.foregroundColor:
   UIColor.black], for: .normal)
           
           yearpickerToolbar?.items = [cancelButton, flexSpace, doneButton]
           textfield.inputAccessoryView = yearpickerToolbar }
   
   @objc func cancelBtnClicked(_ button: UIBarButtonItem?) {
           self.view.endEditing(true)
           
       }
   
       @objc func doneBtnClicked(_ button: UIBarButtonItem?) {
           self.view.endEditing(true)
       }

Swift 2.2 /我用了Dx_的答案。然而，我希望所有的键盘都有这个功能。所以在我的基类中，我把代码:

func addDoneButtonForTextFields(views: [UIView]) {
    for view in views {
        if let textField = view as? UITextField {
            let doneToolbar = UIToolbar(frame: CGRectMake(0, 0, self.view.bounds.size.width, 50))

            let flexSpace = UIBarButtonItem(barButtonSystemItem: .FlexibleSpace, target: nil, action: nil)
            let done = UIBarButtonItem(title: "Done", style: .Done, target: self, action: #selector(dismissKeyboard))

            var items = [UIBarButtonItem]()
            items.append(flexSpace)
            items.append(done)

            doneToolbar.items = items
            doneToolbar.sizeToFit()

            textField.inputAccessoryView = doneToolbar
        } else {
            addDoneButtonForTextFields(view.subviews)
        }
    }
}

func dismissKeyboard() {
    dismissKeyboardForTextFields(self.view.subviews)
}

func dismissKeyboardForTextFields(views: [UIView]) {
    for view in views {
        if let textField = view as? UITextField {
            textField.resignFirstResponder()
        } else {
            dismissKeyboardForTextFields(view.subviews)
        }
    }
}

然后只需调用addDoneButtonForTextFields在self.view.subviews在viewDidLoad(或willDisplayCell如果使用表格视图)添加完成按钮到所有键盘。

这是我遇到的最简单的解决办法。我是从《iOS 5开发入门》这本书中学到的。

假设数字字段名为numberField。

In ViewController, add the following method: -(IBAction)closeKeyboard:(id)sender; In ViewController.m, add the following code: -(IBAction)closeKeyboard:(id)sender { [numberField resignFirstResponder]; } Go back to nib file. Open Utilities pan. Open the Identity inspector under Utilities pan. Click on the View (in nib file) once. Make sure you have not clicked on any of the items in the view. For the sake of clarification, you should see UIView under Class in Identity inspector. Change the class from UIView to UIControl. Open Connection Inspector. Click and drag Touch Down and drop the arrow on File Owner icon. (FYI... File Owner icon is displayed on the left of View and appears as a hollow cube with yellow frame.) Select the method: closeKeyboard. Run the program.

现在，当你点击视图背景的任何地方，你应该能够解散键盘。

希望这能帮助你解决问题。: -)

所有这些关于找到键盘视图并在第三行添加done按钮的实现(这就是为什么按钮。y = 163 b/c键盘的高度是216)是脆弱的，因为iOS不断改变视图层次结构。例如，上述代码都不适用于iOS9。

我认为更安全的方法是找到最顶层的视图，通过[[UIApplication sharedApplication] windows] lastObject]，并在它的左下角添加按钮，doneButton.frame = CGRectMake(0, screen_height - 53,106,53);//人像模式