ios键盘高度

- (void)viewDidLoad
{
    [super viewDidLoad];

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

- (void)didReceiveMemoryWarning
{
    [super didReceiveMemoryWarning];
    // Dispose of any resources that can be recreated.
      [[NSNotificationCenter defaultCenter]removeObserver:self];
}
-(void)keyboardWillShow:(NSNotification*)notification{
    
    NSDictionary*info=[notification userInfo];
    CGSize kbSize=[[info objectForKey:UIKeyboardFrameEndUserInfoKey]CGRectValue].size;
    //
    NSValue *animationDurationValue = [info objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    
    NSTimeInterval animationDuration;
    
    [animationDurationValue getValue:&animationDuration];
    NSLog(@"keyboard changed, keyboard width = %f, height = %f,animationDuration =%f",
          
          kbSize.width,kbSize.height,animationDuration);
    
}