I am trying to add subview to UITabBar which should be behind other UITabBar Subviews.
I added the subview like this in my subclass of UITabBarController:
self.tabBar.addSubview(CustomTabBarController.xView!)
and then I send it to back as below:
self.tabBar.sendSubview(toBack: CustomTabBarController.xView!)
Problem is it doesn't go back and always appear infront. Also, even when this is the case, I am able to tap on tabbaritems. Is something wrong with UITabBar properties? or else, What am I doing wrong?
A view that a subview of view A can't be behind view A. Think of a subview as being on the page of it's parent view.
It's also likely that a tab bar does not allow you to add subviews to it. Apple's UI controls are usually built to fully manage their view hierarchies, and the results of trying to insert subviews or otherwise mess with the view hierarchy are often undefined.
If you want a view to be behind another view the two views need to have the same parent view. You need to tell the tab bar's superview to add your new view behind the tab bar:
self.tabBar.superview. insertSubview(CustomTabBarController.xView!,
belowSubview: self.tabBar)
Also note that your use of force-unwrapping is ill-advised
Related
I have a UIViewController that contains a UICollectionView pinned to all edges of the view. This view controller is inside a UINavigationController.
I want to gradually hide the navigation bar as I scroll down in the collection view. At the point that I have scrolled the distance of the height of the nav bar, the nav bar should be completely hidden. If I scroll back up it should gradually show the nav bar.
I have tried all the open source navigation bars on github, but none of them work correctly with iOS 12.
How can I achieve this?
UICollectionView is a subclass of UIScrollView and therefore you have access to its scrollViewDidScroll delegate method. Your UIViewController is also owned by its navigation controller, so you can create an instance property in the view controller, like navigationDelegate: UINavigationController?, that will act as a delegate. In the navigation controller, set that property equal to self and manipulate the nav bar however you want through the scroll delegate. Absolutely no need for third-party scripting for something this standard and basic.
How can I place a UIView overtop of a Navigation Controller? Is this possible without making my own custom navigation bar and custom tab bar controller out of UIViews?
Let's say I have a UITabBarController and I want to present a blur view overtop of the entire thing. For the blur view, I'm using the UIVisualEffectView. But i want the blurview to take up the entire screen including the top navigation bar and the bottom tab bar. If I push a new view controller, that will take up the entire screen, but then I can't see through it to what's underneath (the tab bar controller's contents).
I could simply hide the navigation bar and tab bar when I animate in the blur view, but that looks awkward because you see the content in the collectionview shift because the navigation bar is hiding... I'd rather not see that shift in the content when the blurview comes up.
Here's a UITabBarController with stuff in it.
I want a blur view to cover everything and to be able to see through to the entire UITabBarController and the stuff underneath.
One way is to add the UIView as a subview of the key window. See this post for how to get the key window. However, it's generally best to keep to your own view hierarchy, so...
Another way might be to present a new view controller as a fullscreen modal, and apply the blur/transparency to that modal view.
I'm trying to add a toolBar under the navigationBar in a UITableViewController. This can easily be done by StoryBoard Builder, but when i scroll down or up it will scroll. My question is then how i can add a Toolbar under navigationBar without the toolBar moving on tableView Scroll?
illustration
Don't use a table view controller. Use a simple view controller which has an explicit outlet to a table view which is a sub view. Then you can also have a sub view which is the toolbar above the table view (and anything else you might need above or below the table in future).
Alternatively you can set the tableHeaderView (and tableFooterView) of the table view itself.
I don't know why UITableView has bottom inset automatically despite I make UITabBarController be hidden by calling [setHidden:YES] before.
The view controller who has UITableView is a child of UITabBarController. I already know that automaticallyAdjustsScrollViewInsets helps any UIScrollView get proper 'contentInset' depending on status of it's container view controller.
So, I expected that UITableView's bottom contentInset will be 0 if UITabBar is hidden. But, doesn't do that.
Although automaticallyAdjustsScrollViewInsets is YES, should I manually adjust that value when UITabBar is hidden?
Tab bars have never been meant to be hidden - after all why have a UITabBarController if you want to hide the tab bar. In the documentation, you are warned not to modify the tab bar object directly:
You should never attempt to manipulate the UITabBar object itself
stored in this property.
This is exactly what you are doing when setting it to hidden.
In iOS6 this has worked, but now in iOS7, it doesn't. And it seems very error prone to hide it. When you finally manage to hide it, if the app goes to the background and returns, Apple's layout logic overrides your changes. There are many such triggers.
My suggestion is to change your design. Perhaps display the data modally.
Putting this here for anyone who gets this problem for nested view controllers.
My view controller containment hierarchy is:
UINavigationController
|--UIViewController
|--UITabBarController
|--UIViewController
The last view controller has a UITableView whose scrollIndicatorInsets keep getting offset by the tab bar controller's UITabBar height even if it is hidden.
Solution: Set automaticallyAdjustsScrollViewInsets to false in the view controller that contains the tab bar controller (and is inside the UINavigationController). No need to set additional properties in the tab bar controller itself and the second view controller where the UITableView is.
I have a UIScrollView added and positioned via Interface Builder, as part of a view controller on a navigation controller stack. When I push a new view controller onto the stack, then pop that new view controller, the UIScrollView in the original view has drifted upwards by exactly 52 pixels.
This ONLY happens on the device, and not the Simulator.
Any ideas what might be causing this? I can fix it retroactively with calls to re-position in the viewWillAppear/viewWillAppear, but for some reason on a very few occasions even this doesn't work, so I'd really like to fix the root cause. Thanks!
Note in response to comments: I'm hiding the navigation bar in the pushed view controller, but not the original view controller. Also note that there are several other UIView elements on the original view controller, but it's only the UIScrollView which is moving out of position.
Update: not hiding the navbar in the pushed view controller has no impact on the UIScrollView problem - but thanks for the suggestion, commenters.
Fix: if the navigation bar is being hidden on a view controller, and you don't want any subviews (which you added via Interface Builder) automatically re-positioning in unexpected ways, make sure the struts on the subviews are set to be fixed.