获取键盘的高度

- (void)keyboardWillShow:(NSNotification *)notification

{

    //动画效果

   NSDictionary *userInfo = [notificationuserInfo];

    NSValue* aValue = [userInfoobjectForKey:UIKeyboardFrameEndUserInfoKey];

   CGRect keyboardRect = [aValueCGRectValue];

    NSValue *animationDurationValue = [userInfoobjectForKey:UIKeyboardAnimationDurationUserInfoKey];

}

// x:0.000000,y:264.000000,width:320.000000,heigh:216.000000