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];
}

我在这里描述了iOS 4.2+的一个解决方案，但键盘出现后，解散按钮会消失。这并不可怕，但也不理想。

上面链接的问题中描述的解决方案包括一种更优雅的消除按钮的错觉，我将按钮淡出并垂直移动，以提供键盘和按钮一起消除的外观。

这是最新的代码。只包括 在你的viewController中导入"UIViewController+NumPadReturn.h"

这里是。h

#import <Foundation/Foundation.h>
#import <UIKit/UIKit.h>

@interface UIViewController (NumPadReturn)



@end

还有。m

#import "UIViewController+NumPadReturn.h"


@implementation UIViewController (NumPadReturn)

-(void) viewDidLoad{
    // add observer for the respective notifications (depending on the os version)
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
        [[NSNotificationCenter defaultCenter] addObserver:self 
                                                 selector:@selector(keyboardDidShow:) 
                                                     name:UIKeyboardDidShowNotification 
                                                   object:nil];     
    } else {
        [[NSNotificationCenter defaultCenter] addObserver:self 
                                                 selector:@selector(keyboardWillShow:) 
                                                     name:UIKeyboardWillShowNotification 
                                                   object:nil];
    }

}


- (void)keyboardWillShow:(NSNotification *)note {
    // if clause is just an additional precaution, you could also dismiss it
    if ([[[UIDevice currentDevice] systemVersion] floatValue] < 3.2) {
        [self addButtonToKeyboard];
    }
}

- (void)keyboardDidShow:(NSNotification *)note {
    // if clause is just an additional precaution, you could also dismiss it
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
        [self addButtonToKeyboard];
    }
}

- (void)addButtonToKeyboard {
    // create custom button
    UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
    doneButton.frame = CGRectMake(0, 163, 106, 53);
    doneButton.adjustsImageWhenHighlighted = NO;
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.0) {
        [doneButton setImage:[UIImage imageNamed:@"DoneUp3.png"] forState:UIControlStateNormal];
        [doneButton setImage:[UIImage imageNamed:@"DoneDown3.png"] forState:UIControlStateHighlighted];
    } else {        
        [doneButton setImage:[UIImage imageNamed:@"DoneUp.png"] forState:UIControlStateNormal];
        [doneButton setImage:[UIImage imageNamed:@"DoneDown.png"] forState:UIControlStateHighlighted];
    }
    [doneButton addTarget:self action:@selector(doneButton:) forControlEvents:UIControlEventTouchUpInside];
    // locate keyboard view
    UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
    UIView* keyboard;
    for(int i=0; i<[tempWindow.subviews count]; i++) {
        keyboard = [tempWindow.subviews objectAtIndex:i];
        // keyboard found, add the button
        if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
            if([[keyboard description] hasPrefix:@"<UIPeripheralHost"] == YES)
                [keyboard addSubview:doneButton];
        } else {
            if([[keyboard description] hasPrefix:@"<UIKeyboard"] == YES)
                [keyboard addSubview:doneButton];
        }
    }
}

- (void)doneButton:(id)sender {
    NSLog(@"doneButton");
    [self.view endEditing:TRUE];
}



@end

如果你事先知道要输入的数字数量(例如一个4位数的PIN)，你可以在按4次键后自动退出，就像我对这个类似问题的回答:

取消数字垫

在这种情况下，不需要额外的done按钮。

如果你有多个数字字段，我建议子类化UITextField来创建一个NumericTextField，它总是显示一个带有done按钮的数字键盘。然后，简单地将你的数值字段与接口构建器中的这个类关联起来，你就不需要在任何视图控制器中添加任何额外的代码。下面是我在Xcode 8.0中使用的Swift 3.0类。

class NumericTextField: UITextField {
   let numericKbdToolbar = UIToolbar()

    // MARK: Initilization
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.initialize()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.initialize()
    }

    // Sets up the input accessory view with a Done button that closes the keyboard
    func initialize()
    {
        self.keyboardType = UIKeyboardType.numberPad

        numericKbdToolbar.barStyle = UIBarStyle.default
        let space = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.flexibleSpace, target: nil, action: nil)
        let callback = #selector(NumericTextField.finishedEditing)
        let donebutton = UIBarButtonItem(barButtonSystemItem: UIBarButtonSystemItem.done, target: self, action: callback)
        numericKbdToolbar.setItems([space, donebutton], animated: false)
        numericKbdToolbar.sizeToFit()
        self.inputAccessoryView = numericKbdToolbar
    }

    // MARK: On Finished Editing Function
    func finishedEditing()
    {
        self.resignFirstResponder()
    }
}

斯威夫特4.2

class NumericTextField: UITextField {
    let numericKbdToolbar = UIToolbar()

    // MARK: Initilization
    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)
        self.initialize()
    }

    override init(frame: CGRect) {
        super.init(frame: frame)
        self.initialize()
    }

    // Sets up the input accessory view with a Done button that closes the keyboard
    func initialize()
    {
        self.keyboardType = UIKeyboardType.numberPad

        numericKbdToolbar.barStyle = UIBarStyle.default
        let space = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.flexibleSpace, target: nil, action: nil)
        let callback = #selector(NumericTextField.finishedEditing)
        let donebutton = UIBarButtonItem(barButtonSystemItem: UIBarButtonItem.SystemItem.done, target: self, action: callback)
        numericKbdToolbar.setItems([space, donebutton], animated: false)
        numericKbdToolbar.sizeToFit()
        self.inputAccessoryView = numericKbdToolbar
    }

    // MARK: On Finished Editing Function
    @objc func finishedEditing()
    {
        self.resignFirstResponder()
    }
}

如果我们告诉视图控制器的视图结束编辑，我们也可以让“user touched somewhere else”解决方案更简单:

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

      [self.view endEditing:YES]; //YES ignores any textfield refusal to resign
 }

．.． 假设“触摸其他地方会取消键盘”是视图中任何其他可编辑字段所期望的行为。