另一个解决方案。如果屏幕上有其他非数字填充文本字段，则完美。

- (void)viewDidLoad
{
    [super viewDidLoad];

    UIToolbar* numberToolbar = [[UIToolbar alloc]initWithFrame:CGRectMake(0, 0, 320, 50)];
    numberToolbar.barStyle = UIBarStyleBlackTranslucent;
    numberToolbar.items = @[[[UIBarButtonItem alloc]initWithTitle:@"Cancel" style:UIBarButtonItemStyleBordered target:self action:@selector(cancelNumberPad)],
                         [[UIBarButtonItem alloc]initWithBarButtonSystemItem:UIBarButtonSystemItemFlexibleSpace target:nil action:nil],
                         [[UIBarButtonItem alloc]initWithTitle:@"Apply" style:UIBarButtonItemStyleDone target:self action:@selector(doneWithNumberPad)]];
    [numberToolbar sizeToFit];
    numberTextField.inputAccessoryView = numberToolbar;
}

-(void)cancelNumberPad{
    [numberTextField resignFirstResponder];
    numberTextField.text = @"";
}

-(void)doneWithNumberPad{
    NSString *numberFromTheKeyboard = numberTextField.text;
    [numberTextField resignFirstResponder];
}

我所见过的技巧是创建一个与整个视图大小相同的自定义透明按钮，然后在其click方法中，让文本字段辞去first responder。因此，用户可以单击字段之外的任何地方来取消键盘。

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。

我发现@user1258240的答案是非常简洁的，因为这并不像设置一个returnKeyType属性那么简单。

只是想贡献我自己的“可重用”方法:

func SetDoneToolbar(field:UITextField) {
    let doneToolbar:UIToolbar = UIToolbar()

    doneToolbar.items=[
        UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: self, action: nil),
        UIBarButtonItem(title: "Done", style: UIBarButtonItem.Style.plain, target: self, action: #selector(ViewController.dismissKeyboard))
    ]

    doneToolbar.sizeToFit()
    field.inputAccessoryView = doneToolbar
}

override func viewDidLoad() {
    super.viewDidLoad()

    SetDoneToolbar(field: UITextField_1)
    SetDoneToolbar(field: UITextField_2)
    SetDoneToolbar(field: UITextField_3)
    SetDoneToolbar(field: UITextField_N)
}

 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)
       }

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