smoothly Hidden navigation bar - ios

Question

How can I do it with out resize view frame (or tableView)?
I use this code and I have resized view then I scroll down/up
I use code, not storyboard
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer class] == [UIPanGestureRecognizer class])
{
UIPanGestureRecognizer *panGestureRec = (UIPanGestureRecognizer *)gestureRecognizer;
CGPoint distance = [panGestureRec translationInView:self.tableView];
if (distance.y > 0 || distance.y < 0)
{
if (distance.y > 0) // down
{
//NSLog(#"user swiped down");
[self.navigationController setNavigationBarHidden:YES animated:YES];
} else if (distance.y < 0) //up
{
//NSLog(#"user swiped up");
[self.navigationController setNavigationBarHidden:NO animated:YES];
}
return NO;
} else {
return YES;
}
}
return YES;
}

Answer 1

Try this code . This will give smooth animation (Used UIView Animation property)
- (BOOL)gestureRecognizerShouldBegin:(UIGestureRecognizer *)gestureRecognizer
{
if ([gestureRecognizer class] == [UIPanGestureRecognizer class])
{
[UIView beginAnimations:nil context:NULL];
[UIView setAnimationDuration:2];
UIPanGestureRecognizer *panGestureRec = (UIPanGestureRecognizer *)gestureRecognizer;
CGPoint distance = [panGestureRec translationInView:self.tableView];
if (distance.y > 0 || distance.y < 0)
{
if (distance.y > 0) // down
{
//NSLog(#"user swiped down");
[self.navigationController setNavigationBarHidden:YES animated:YES];
} else if (distance.y < 0) //up
{
//NSLog(#"user swiped up");
[self.navigationController setNavigationBarHidden:NO animated:YES];
}
return NO;
} else {
return YES;
}
[UIView commitAnimations];
}
return YES;