按钮动作方法不激活

Question

(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:@"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:0];
    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 ([[[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(@"Input: %@", textField.text);
    [textField resignFirstResponder];
}

动作方法运行正常。但是当在iOS 8.3 beta 4版本中测试时，动作方法不会调用.. ????