我修改了Bryan的解决方案，使其更加健壮，这样它就可以很好地与可能出现在同一视图中的其他类型的键盘一起使用。描述如下:

在iOS numpad UIKeyboard上创建DONE按钮

我会试着在这里解释它，但大部分代码都是要查看的，不容易放在这里

对于Swift 2.2，我使用这个

func addDoneButtonOnKeyboard() {
    let doneToolbar: UIToolbar = UIToolbar(frame: CGRectMake(0, 0, self.view.bounds.size.width, 50))

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

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

    doneToolbar.items = items
    doneToolbar.sizeToFit()
    self.productPrice.inputAccessoryView=doneToolbar
}

func finishDecimalKeypad() {
    self.productPrice?.resignFirstResponder()
}

一个更简单的解决方案

- (void)touchesBegan:(NSSet *)touches withEvent:(UIEvent *)event 
{ 
    [super touchesBegan:touches withEvent:event];

    [textViewInstance1 resignFirstResponder];
    [textViewInstance2 resignFirstResponder];
    [textField resignFirstResponder];
}

以下是改编自Luda对斯威夫特的回答:

在你的UIViewController子类put的声明中

let numberToolbar: UIToolbar = UIToolbar()

在ViewDidLoad中放入:

    numberToolbar.barStyle = UIBarStyle.BlackTranslucent
    numberToolbar.items=[
        UIBarButtonItem(title: "Cancel", style: UIBarButtonItemStyle.Bordered, target: self, action: "hoopla"),
        UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.FlexibleSpace, target: self, action: nil),
        UIBarButtonItem(title: "Apply", style: UIBarButtonItemStyle.Bordered, target: self, action: "boopla")
    ]

    numberToolbar.sizeToFit()

    textField.inputAccessoryView = numberToolbar //do it for every relevant textfield if there are more than one 

并添加函数hoopla和hoopla(可以随意选择其他名称，只需相应地更改ViewDidLoad中的选择器名称

func boopla () {
    textField.resignFirstResponder()
}

func hoopla () {
    textField.text=""
    textField.resignFirstResponder()
}

使用扩展的Swift 3解决方案。如果你在你的应用程序中有几个数值的UITextField对象，这是理想的，因为它可以灵活地决定，对于每个UITextField，当点击完成或取消时是否执行自定义操作。

//
//  UITextField+DoneCancelToolbar.swift
//

import UIKit

extension UITextField {
    func addDoneCancelToolbar(onDone: (target: Any, action: Selector)? = nil, onCancel: (target: Any, action: Selector)? = nil) {     
        let onCancel = onCancel ?? (target: self, action: #selector(cancelButtonTapped))
        let onDone = onDone ?? (target: self, action: #selector(doneButtonTapped))

        let toolbar: UIToolbar = UIToolbar()
        toolbar.barStyle = .default
        toolbar.items = [
            UIBarButtonItem(title: "Cancel", style: .plain, target: onCancel.target, action: onCancel.action),
            UIBarButtonItem(barButtonSystemItem: .flexibleSpace, target: self, action: nil),
            UIBarButtonItem(title: "Done", style: .done, target: onDone.target, action: onDone.action)
        ]
        toolbar.sizeToFit()

        self.inputAccessoryView = toolbar
    }

    // Default actions:  
    func doneButtonTapped() { self.resignFirstResponder() }
    func cancelButtonTapped() { self.resignFirstResponder() }
}

使用默认动作的示例:

//
// MyViewController.swift
//

@IBOutlet weak var myNumericTextField: UITextField! {
    didSet { myNumericTextField?.addDoneCancelToolbar() }
}

使用自定义完成动作的示例:

//
// MyViewController.swift
//

@IBOutlet weak var myNumericTextField: UITextField! {
    didSet { 
        myNumericTextField?.addDoneCancelToolbar(onDone: (target: self, action: #selector(doneButtonTappedForMyNumericTextField))) 
    }
}

func doneButtonTappedForMyNumericTextField() { 
    print("Done"); 
    myNumericTextField.resignFirstResponder() 
}

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];
}