First. set alpha = 0.
click HOME back to backgroud, then click app back to app.
The alpha will set 1 auto automaticly.
How to set the navigationBar alpha = 0 forever.
If you want programatically try this:
If you want no navigation bar, and you want the content to be adjusted up to where the navigation bar normally would be, you should use
self.navigationController.navigationBarHidden = YES;
Otherwise use self.navigationController.navigationBar.hidden = YES; gives you a space where the navigationBar is.
when you come back from second view controller to first view controller then you have to implement some code in viewWillAppear method :
code
viewController1
-(void)viewWillAppear:(BOOL)animated
{
[super viewWillAppear:YES];
self.navigationController.navigationBarHidden = YES;
}
viewController2
[self.navigationController popViewControllerAnimated:YES];
Related
I hide my tab bar like so:
self.tabBarController.tabBar.hidden = YES;
And because now there is a black bar where it once stood I stretch the view which is a UIWebView on top(or is it under?) that empty space. The UIWebView is in a UIViewController. I do that with a constraint which by default is like so:
The code for the constraint:
if(self.tabBarController.tabBar.hidden){
self.webviewBottomConstrain.constant = -self.tabBarController.tabBar.frame.size.height;
}else{
self.webviewBottomConstrain.constant = 0;
}
However if I tap the device on the place where the TabBar was it will not execute. It is as if there is something invisible there with the size of the tab bar. I have also tried hiding it the way this thread sugests. Still the same result.
Update: It seems that when you tap on the invisible tab bar the tap is recognized by the tab bar and not by the view that is visible under the tab bar
self.extendedLayoutIncludesOpaqueBars = YES;
this will solve you problem
You hide your tabBar by setting its hidden property to NO? Try setting it to YES. Unless I am misunderstanding what you are trying to do, it seems like your tab bar is not hidden with that code.
Another thing I would check is to see if User Interaction Enabled is checked for the web view. If it is not, that can seem like there is something invisible blocking you from interacting with your view.
Well I am using quite ugly hack to fix this. I am hiding the tab bar in another way now:
if (shouldShow) {
self.hidesBottomBarWhenPushed = NO;
UIViewController *someView = [[UIViewController alloc] init];
[self.navigationController pushViewController:someView animated:NO];
[self.navigationController popToViewController:self animated:NO];
} else if (shouldHide) {
self.hidesBottomBarWhenPushed = YES;
self.tabBarController.hidesBottomBarWhenPushed = YES;
self.navigationController.hidesBottomBarWhenPushed = YES;
UIViewController *someView = [[UIViewController alloc] init];
[self.navigationController pushViewController:someView animated:NO];
[self.navigationController popToViewController:self animated:NO];
}
I do need that random view because I cannot push the view on itself.
I had the same issue when hiding the tab bar by moving it offscreen to the bottom. My custom UITabBarViewController was intercepting the touch events in the area vacated by the tab bar, so instead of changing the frame of the tab bar to move the tab bar offscreen, I extended the height of my tab bar view controller so that the tab bar still moved offscreen, but the child view above the tab bar now filled that space. This allowed the touches to be received by the child view.
As you may see with view hierarchy instrument, UITabBar is not directly blocking your tap, but your current view controller's view height is not full screen:
So, the tap doesn't response because your finger's y position is higher than view's maxY.
Code like this (inside your UITabBarController) will expand your view's height, according to tabbar visibility, and all tap events will work correctly.
func updateTabBarAppearanceWithDegree(_ degree: CGFloat) {
let screenHeight = UIScreen.main.bounds.size.height
let tabBarHeight = self.tabBar.frame.size.height
self.tabBar.frame.origin.y = screenHeight - tabBarHeight * degree
self.tabBar.alpha = degree
let currentNavigation = self.selectedViewController as? UINavigationController
if let currentTopView = currentNavigation?.viewControllers.last?.view {
currentTopView.frame.size.height = self.tabBar.frame.origin.y
}
}
I'm hiding the navigationbar on a certain view, and when the user presses a button on the view, i'm pushing it to the next view.
In the next view, I am not longer hiding the nav bar and as expected it becomes visible. When hitting back however, the navbar on the first view also becomes (somehow) visible.
I'm hiding the top navbar like this:
self.navigationController.navigationBar.hidden = YES;
And I'm making it visible like this:
self.navigationController.navigationBar.hidden = NO;
I wonder what could be wrong with this, as it's quite basic but somehow has a glitch.
In Parent VC's viewWillAppear method hide the navigation bar.
-(void)viewWillAppear:(BOOL)animated {
self.navigationController.navigationBar.hidden = YES;
}
I have a table view A which is segued to a view B.
In A, there is a nav bar on the top, and below is the table.
When I press a row in A's table, B is pushed.
In B's viewWillAppear, I have the following code.
-(void)viewWillAppear:(BOOL)animated
{
self.wantsFullScreenLayout = YES;
[self.navigationController.navigationBar setBackgroundImage:nil forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.barStyle = UIBarStyleBlackTranslucent;
}
This makes extends the view so that below the status bar, I have Nav bar and the UIView overlapped.
I also have viewWillDisappear
-(void)viewWillDisappear:(BOOL)animated
{
if ([self.navigationController.viewControllers indexOfObject:self]==NSNotFound) {
// back button was pressed. We know this is true because self is no longer in the navigation stack.
self.wantsFullScreenLayout = NO;
[self.navigationController.navigationBar setBackgroundImage:[UIImage imageNamed:#"navigationbar_bg.png"] forBarMetrics:UIBarMetricsDefault];
self.navigationController.navigationBar.translucent = NO;
}
}
So when the user press back button, it will undo the fullscreen mode so that the view and nav bar won't overlap. THE ISSUE IS, when I press back button and the previous screen A is shown, strangely the table view still appears overlapped with the nav bar.
I even tried to put self.wantsFullScreenLayout = NO in A's willViewAppear but to no avail.
Shouldn't A shrink the tableview and be located under Nav bar? Can anyone let me know what is worng and how to solve this issue?
Thanks in advance!
Instead of putting the code in viewWillDisappear method, try to put the same code in the viewWillAppear method of the previous view controller.
1) What is the difference between the three lines of code below?
2) Also why does only the third line of code work if I'm returning to a viewController and the previous viewController has set the navigationBar to hidden through the same approach [self.navigationController setNavigationBarHidden:NO] my assumption was that all three lines do the same thing?
self.navigationController.navigationBar.hidden = NO;
[self.navigationController.navigationBar setHidden:NO];
[self.navigationController setNavigationBarHidden:NO];
Follow up:
Why when I need to run this code:
[self.navigationController.navigationBar setBackgroundImage:incorrectAnswerNavigationBarBackgroundImage forBarMetrics:UIBarMetricsDefault];
It only works, working being setting the background image, otherwise the nav bar is just white.
if I have both these lines:
[self.navigationController setNavigationBarHidden:NO];
self.navigationController.navigationBar.hidden = NO;
If I leave out self.navigationController.navigationBar.hidden = NO; the space for the nav bar pops down but it's just white, there is no background image. If I have both lines it works and there is a background image.
The first two are functionally identical; the difference being one uses the dot notation while the other doesn't. These two methods both fire - (void) setHidden:(BOOL)hide on the navigationBar property on the navigation controller.
Now the third one is a completely different method. It's - (void) setNavigationBarHidden:(BOOL)hide and is defined on UINavigationController. The reason why this one works is this method is informing the navigation controller that you wish the navigation bar to be hidden while the first two manually set the navigation bar to be hidden. The first two's changes are undone if UINavigationController calls any methods that modify the hidden property of the navigation bar, hence why the setNavigationBarHidden: method was created so you'd have a way of informing UINavigationController that no matter what it does, it should hide the navigation bar and not change it to be showing.
EDIT: For the second part of this question, you actually need to be calling - (void)setNavigationBarHidden:(BOOL)hidden animated:(BOOL)animated on UINavigationController. That's the proper documented method for UINavigationController.
I have almost done this in all the application but I have 3 views stacked in navigationController and I need to jump from the third view to the first view.
As I understand I can do this via viewWillDisappear only. But if I try this "jump" I will get the navigationController panel from the second View which with a navigation buttons which cause exceptions/errors.
P.S. Do not advice me to make leftBarButtonitem looking like backBarButtonItem. It is too difficult and I don't know where to find an appropriate image for it.
To my knowledge, you have no choice but to provide your own UIBarButtonItem. You are not permitted from interrupting how UINavigationController works by default. That is, you cannot override the behavior of the back button. You must provide a custom bar button item and set it as the navigation item's left bar button item.
(As a side note, the sort of behavior you're looking for may be an indication of a poor navigation pattern. Back buttons should almost always back out of a navigation hierarchy sequentially.)
Let's say in navigation order your views stacked like top -> 3 -> 2 -> 1 . When you are in this position you can have a flag in your application delegate that shows you will doublePop when backButton pressed as below: ( You are doing this whenever third view appears in the order you mentioned)
MyApplicationDelegate * del = [[UIApplication sharedApplication]delegate];
del.doublePopEnabled = YES;
[del release];
In view 2 :
- (void)viewWillAppear:(BOOL)animated {
[super viewWillAppear:animated];
MyApplicationDelegate * del = [[UIApplication sharedApplication]delegate];
if(del.doublePopEnabled){
//Asssuming you have a reference to your navigationController in your view 2
del.doublePopEnabled = NO;
[del.release]
//Use animated as no if you don't want user to see doublePopping.
self.navigationController popViewControllerAnimated:NO];
}
}
Hope it helps.