我不想走这条路线，因为我的空间很差这是一种在iOS7 num-keypad中投影完成按钮的简单方法。在下面的UITextField的委托方法中，添加一个通知键盘显示。

This is a simple way of projecting a done button in iOS7 num-keypad. In the below delegate method of UITextField, add a notification for keyboard show.

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

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(keyboardWillShow:)
                                             name:UIKeyboardWillShowNotification
                                           object:nil];
}

现在实现方法 keyboardWillShow 如下。这里我们需要对iOS7格外小心。

Now implement the method keyboardWillShow as below. Here we need to take extra care for iOS7.

- (void)keyboardWillShow:(NSNotification *)note {
// create custom button
UIButton *doneButton = [UIButton buttonWithType:UIButtonTypeCustom];
doneButton.frame = CGRectMake(0, 163, 106, 53);
doneButton.adjustsImageWhenHighlighted = NO;
[doneButton setImage:[UIImage imageNamed:@"doneButtonNormal.png"] forState:UIControlStateNormal];
[doneButton setImage:[UIImage imageNamed:@"doneButtonPressed.png"] forState:UIControlStateHighlighted];
[doneButton addTarget:self action:@selector(doneButton:) forControlEvents:UIControlEventTouchUpInside];

if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
    dispatch_async(dispatch_get_main_queue(), ^{
        UIView *keyboardView = [[[[[UIApplication sharedApplication] windows] lastObject] subviews] firstObject];
        [doneButton setFrame:CGRectMake(0, keyboardView.frame.size.height - 53, 106, 53)];
        [keyboardView addSubview:doneButton];
        [keyboardView bringSubviewToFront:doneButton];

        [UIView animateWithDuration:[[note.userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey] floatValue]-.02
                              delay:.0
                            options:[[note.userInfo objectForKey:UIKeyboardAnimationCurveUserInfoKey] intValue]
                         animations:^{
                             self.view.frame = CGRectOffset(self.view.frame, 0, 0);
                         } completion:nil];
    });
}else {
    // locate keyboard view
    dispatch_async(dispatch_get_main_queue(), ^{
        UIWindow* tempWindow = [[[UIApplication sharedApplication] windows] objectAtIndex:1];
        UIView* keyboard;
        for(int i=0; i<[tempWindow.subviews count]; i++) {
            keyboard = [tempWindow.subviews objectAtIndex:i];
            // keyboard view found; add the custom button to it
            if([[keyboard description] hasPrefix:@"UIKeyboard"] == YES)
                [keyboard addSubview:doneButton];
        }
    });
  }
}

现在将此宏添加到合适的标题以检测SYSTEM_VERSION

Now add this macro to suitable header to detect the SYSTEM_VERSION

#define SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO（v）（[[[UIDevice currentDevice] systemVersion] compare：v options：NSNumericSearch]！= NSOrderedAscending）