hide and show navbar when scroll uiwebview - iphone

Question

i need help, i am trying to build a app in which i have a viewcontroller with a uiwebview and a navbar with 2 buttons on it. what i want to do is that when user scroll uiwebview navbar automatically hides like slid up sort of. but is not working they way i want it to work. let me post code here.
In viewdidload i put this.
[webPage.scrollView setDelegate:self];
and then i have this method
- (void) scrollViewDidScroll:(UIScrollView *)scrollView {
if(scrollView.contentOffset.y == 0) {
//show
NSLog(#"Show");
[self.navigationController setNavigationBarHidden:NO animated:YES];
} else {
NSLog(#"Hide");
[self.navigationController setNavigationBarHidden:YES animated:YES];
//hide
}
}
it NSLog correctly but nothing else navbar still stays. :(

Answer 1

Easy as add this on the ViewController implementation file (.m):
- (void)viewDidLoad
{
[super viewDidLoad];
self.webView.scrollView.delegate = self;
}
#pragma mark - UIScrollViewDelegate Methods
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
self.lastOffsetY = scrollView.contentOffset.y;
}
- (void) scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
bool hide = (scrollView.contentOffset.y > self.lastOffsetY);
[[self navigationController] setNavigationBarHidden:hide animated:YES];
}
AND don't forget to add UIScrollViewDelegate protocol in the header file (.h) :
#interface MyViewController : UIViewController <UIScrollViewDelegate>
...
#end

Answer 2

You can try this:
1. Declare the navigation bar, a constant with your navigation bar height and 2 BOOL variables:
UINavigationBar *navBar;
static const CGFloat kNavBarHeight = 60.0f;
BOOL webViewScrollIsDragging;
BOOL webViewScrollIsDecelerating;
2. In viewDidLoad write the following:
[webView.scrollView setContentInset:UIEdgeInsetsMake(kNavBarHeight, 0, 0, 0)];
[webView.scrollView setScrollIndicatorInsets:UIEdgeInsetsMake(kNavBarHeight, 0, 0, 0)];
[webView.scrollView setContentOffset:CGPointMake(0, -kNavBarHeight) animated:NO];
webView.scrollView.delegate = self;
then initialize and add your UINavigationBar as a subview to self.view at origin (Also make sure that your UIWebView has the same origin, i.e (0,0)).
3. Implement UIScrollViewDelegate methods (Don't forget to add UIScrollViewDelegate protocol):
#pragma mark - UIScrollViewDelegate Methods
- (void)scrollViewDidScroll:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
if (scrollView.contentOffset.y == 1 && !webViewScrollIsDragging && !webViewScrollIsDecelerating)
{
[UIView animateWithDuration:0.3
delay:0.0
options: UIViewAnimationCurveEaseOut
animations:^(void) {
CGRect navBarFrame = CGRectMake(0,-scrollView.contentOffset.y-kNavBarHeight, self.view.bounds.size.width, kNavBarHeight);
navBar.frame = navBarFrame;
}
completion:nil];
}
else
{
CGRect navBarFrame = CGRectMake(0,-scrollView.contentOffset.y-kNavBarHeight, self.view.bounds.size.width, kNavBarHeight);
navBar.frame = navBarFrame;
}
if (scrollView.contentOffset.y < -kNavBarHeight)
{
[webview.scrollView setScrollIndicatorInsets:UIEdgeInsetsMake(fabsf(scrollView.contentOffset.y), 0, 0, 0)];
}
}
}
- (void)scrollViewWillBeginDragging:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDragging = YES;
}
}
- (void) scrollViewDidEndDragging:(UIScrollView *)scrollView willDecelerate:(BOOL)decelerate
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDragging = NO;
}
}
- (void) scrollViewWillBeginDecelerating:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDecelerating = YES;
}
}
- (void) scrollViewDidEndDecelerating:(UIScrollView *)scrollView
{
if (scrollView == webview.scrollView)
{
webViewScrollIsDecelerating = NO;
}
}

Answer 3

In iOS8.0 and later
just use one line code:
self.navigationController.hidesBarsOnSwipe = YES;
/// When the user swipes, the navigation controller's navigationBar & toolbar will be hidden (on a swipe up) or shown (on a swipe down). The toolbar only participates if it has items.
// #property (nonatomic, readwrite, assign) BOOL hidesBarsOnSwipe NS_AVAILABLE_IOS(8_0) __TVOS_PROHIBITED;
When sliding down will hide the navigation bar (and become a transparent state bar), when the slide will be displayed on the navigation bar, the process with animation