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。

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。

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。

在UIKeyboardTypeNumberPad和缺少返回键的解决方案很好，但只有当屏幕上没有其他非数字pad文本字段时。

我把这段代码变成一个UIViewController你可以简单地子类化它来让数字垫工作。您需要从上面的链接获取图标。

NumberPadViewController.h:

#import <UIKit/UIKit.h>

@interface NumberPadViewController : UIViewController {
    UIImage *numberPadDoneImageNormal;
    UIImage *numberPadDoneImageHighlighted;
    UIButton *numberPadDoneButton;
}

@property (nonatomic, retain) UIImage *numberPadDoneImageNormal;
@property (nonatomic, retain) UIImage *numberPadDoneImageHighlighted;
@property (nonatomic, retain) UIButton *numberPadDoneButton;

- (IBAction)numberPadDoneButton:(id)sender;

@end

和NumberPadViewController.m:

#import "NumberPadViewController.h"

@implementation NumberPadViewController

@synthesize numberPadDoneImageNormal;
@synthesize numberPadDoneImageHighlighted;
@synthesize numberPadDoneButton;

- (id)initWithNibName:(NSString *)nibName bundle:(NSBundle *)nibBundle {
    if ([super initWithNibName:nibName bundle:nibBundle] == nil)
        return nil;
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.0) {
        self.numberPadDoneImageNormal = [UIImage imageNamed:@"DoneUp3.png"];
        self.numberPadDoneImageHighlighted = [UIImage imageNamed:@"DoneDown3.png"];
    } else {        
        self.numberPadDoneImageNormal = [UIImage imageNamed:@"DoneUp.png"];
        self.numberPadDoneImageHighlighted = [UIImage imageNamed:@"DoneDown.png"];
    }        
    return self;
}

- (void)viewWillAppear:(BOOL)animated {
    [super viewWillAppear:animated];

    // Add listener for keyboard display events
    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];
    }

    // Add listener for all text fields starting to be edited
    [[NSNotificationCenter defaultCenter] addObserver:self 
                                             selector:@selector(textFieldDidBeginEditing:)
                                                 name:UITextFieldTextDidBeginEditingNotification 
                                               object:nil];
}

- (void)viewWillDisappear:(BOOL)animated {
    if ([[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2) {
        [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                        name:UIKeyboardDidShowNotification 
                                                      object:nil];      
    } else {
        [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                        name:UIKeyboardWillShowNotification 
                                                      object:nil];
    }
    [[NSNotificationCenter defaultCenter] removeObserver:self 
                                                    name:UITextFieldTextDidBeginEditingNotification 
                                                  object:nil];
    [super viewWillDisappear:animated];
}

- (UIView *)findFirstResponderUnder:(UIView *)root {
    if (root.isFirstResponder)
        return root;    
    for (UIView *subView in root.subviews) {
        UIView *firstResponder = [self findFirstResponderUnder:subView];        
        if (firstResponder != nil)
            return firstResponder;
    }
    return nil;
}

- (UITextField *)findFirstResponderTextField {
    UIResponder *firstResponder = [self findFirstResponderUnder:[self.view window]];
    if (![firstResponder isKindOfClass:[UITextField class]])
        return nil;
    return (UITextField *)firstResponder;
}

- (void)updateKeyboardButtonFor:(UITextField *)textField {

    // Remove any previous button
    [self.numberPadDoneButton removeFromSuperview];
    self.numberPadDoneButton = nil;

    // Does the text field use a number pad?
    if (textField.keyboardType != UIKeyboardTypeNumberPad)
        return;

    // If there's no keyboard yet, don't do anything
    if ([[[UIApplication sharedApplication] windows] count] < 2)
        return;
    UIWindow *keyboardWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];

    // Create new custom button
    self.numberPadDoneButton = [UIButton buttonWithType:UIButtonTypeCustom];
    self.numberPadDoneButton.frame = CGRectMake(0, 163, 106, 53);
    self.numberPadDoneButton.adjustsImageWhenHighlighted = FALSE;
    [self.numberPadDoneButton setImage:self.numberPadDoneImageNormal forState:UIControlStateNormal];
    [self.numberPadDoneButton setImage:self.numberPadDoneImageHighlighted forState:UIControlStateHighlighted];
    [self.numberPadDoneButton addTarget:self action:@selector(numberPadDoneButton:) forControlEvents:UIControlEventTouchUpInside];

    // Locate keyboard view and add button
    NSString *keyboardPrefix = [[[UIDevice currentDevice] systemVersion] floatValue] >= 3.2 ? @"<UIPeripheralHost" : @"<UIKeyboard";
    for (UIView *subView in keyboardWindow.subviews) {
        if ([[subView description] hasPrefix:keyboardPrefix]) {
            [subView addSubview:self.numberPadDoneButton];
            [self.numberPadDoneButton addTarget:self action:@selector(numberPadDoneButton:) forControlEvents:UIControlEventTouchUpInside];
            break;
        }
    }
}

- (void)textFieldDidBeginEditing:(NSNotification *)note {
    [self updateKeyboardButtonFor:[note object]];
}

- (void)keyboardWillShow:(NSNotification *)note {
    [self updateKeyboardButtonFor:[self findFirstResponderTextField]];
}

- (void)keyboardDidShow:(NSNotification *)note {
    [self updateKeyboardButtonFor:[self findFirstResponderTextField]];
}

- (IBAction)numberPadDoneButton:(id)sender {
    UITextField *textField = [self findFirstResponderTextField];
    [textField resignFirstResponder];
}

- (void)dealloc {
    [numberPadDoneImageNormal release];
    [numberPadDoneImageHighlighted release];
    [numberPadDoneButton release];
    [super dealloc];
}

@end

享受。

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];
}

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。: -)