键盘通知

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

[[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(keyboardWillHide:) name:UIKeyboardWillHideNotification object:nil];

- (void)keyboardWillShow:(NSNotification *)notification
{
    NSDictionary *userInfo = [notification userInfo];
    NSValue *aValue = [userInfo objectForKey:UIKeyboardFrameEndUserInfoKey];
    CGRect keyboardRect = [aValue CGRectValue];
    keyboardRect = [self.view convertRect:keyboardRect fromView:nil];
   
    CGFloat keyboardTop = keyboardRect.origin.y;
    CGRect newTextViewFrame = self.view.bounds;
    newTextViewFrame.size.height = keyboardTop - self.view.bounds.origin.y;
   
    NSNumber *animationDuration = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval duration = [animationDuration doubleValue];
   
    [UIView animateWithDuration:duration animations:^{
       
    }];
}

- (void)keyboardWillHide:(NSNotification *)notification
{
    NSDictionary* userInfo = [notification userInfo];
    NSNumber *animationDuration = [userInfo objectForKey:UIKeyboardAnimationDurationUserInfoKey];
    NSTimeInterval duration = [animationDuration doubleValue];
   
    [UIView animateWithDuration:duration animations:^{
       
    }];
}