Handle clicks to button in tab bar controller header - ios

I have a tab bar controller with a number of tabs/views. I have added a "Help" bar button item to the tab bar controller's top navigation bar.
How do I handle clicks of this button, ideally depending on which view I am in at the time?
I am simply going to pop up an alert when it is clicked, ie. No navigation required.

Ideally, this "help" tab should not change its behaviour depending on context, i.e., what tab was previously selected. The user will get confused because the content will not be constant.
If you raise a "pop up alert" when the tab is selected, this also seems like a basis for rejection because of bad UX. Selecting a tab should display a new view for that tab. You'd also have to deal with how to move the user back to the previous tab silently, and/or not change the selected tab index. Again, this is troublesome UX.
If you insist on going with this design -- which I believe will get your app rejected -- you can use a UITabBarControllerDelegate to control the behaviour of the UITabBarController.
I recommend you change your design instead.

I've managed to get this working. I think you misunderstood: I have a tab bar control which operates normally by pushing views based on the tab selected. I simply wanted a help button on the right of the navigation bar that would open an alert with information about the tab you happen to be in at the time. I have done it like this:
In viewDidAppear of each view pushed by the tab bar controller:
UIBarBarButtonItem *helpButton = [[UIBarBarButtonItem alloc] initWithTitle:#"Help" style:UIBarButtonItemStylePlain target:self action:#selector(helpButtonPressed))];
self.tabBarController.navigationItem.rightBarButtonItem=helpButton;
I then have the helpButtonPressed function to handle the button click, in my case by popping up and alert with some help info regarding the tab.

Related

IOS Tab Bar Item Popup Submenu

Good Day,
i am looking for a solution of how to make the UITabbar item can popup a submenu.
What part are you having trouble with? It seem pretty simple. Make custom view controller with a tabBar (don't use UITabBarController), for most tab bar items show the correct viewController (ie add as a childViewController), but for more show a popup (a different childViewController). Remember than when the more popup is dismissed to reselect the current tab on the tabbar.

IOS/Objective-C. Detect Press of Tab on Tab Bar Before Leaving View Controller

For a settings view controller, I am currently saving when the user hits the Back Button using viewwilldisappear. However, the settings VC is embedded in a tab bar controller and I've discovered that when the user leaves the VC by moving to another tab, viewwilldisappear does not fire and therefore the settings are not saved. I guess I could save every time someone changes an individual setting, but it would be simpler to save at the end.
Is there any simple way to detect the press of the tab bar controller from within the view controller so I can save settings before leaving if a tab item is pressed?
Take a look at UITabBarControllerDelegate, specifically shouldSelectViewController.
The tab bar controller calls this method in response to the user
tapping a tab bar item. You can use this method to dynamically decide
whether a given tab should be made the active tab.
https://developer.apple.com/reference/uikit/uitabbarcontrollerdelegate?language=objc

IOS using different navigation bars

I'm creating an application where I need to use two different navigation bars. When the application first opens up, the nav1 bar should be displayed with an image and a Login button .. when they login screen appears, there is no nav bar. After login, it goes to a Detail screen where I need to show a back arrow image, a screen title and a menu button with drop down options.
I'm using one View_Controller that all my Views inherit from. I've been working on this for days and I'm so lost, please help.
I'm a little confused about the structure of your app.
As I understand it, you want an initial view that is contained in a UINavigationController. Once someone taps the "Login" UIBarButtonItem on the UINavigationBar, then you have a view come up that is not contained in a UINavigationController (probably because it is a modal view that is outside the navigation flow of your app).
The part I'm confused about is where the Detail view comes in. Is the modally presented view dismissed while the Details view is pushed onto the navigation stack from the initial view? Why does the Details view need a back button? Does going back to the initial view effectively log out the user?
At any rate, you should be able to change the UINavigationBar for every view that is pushed on to the stack (that is also contained in your UINavigationController). If you are using Storyboard, you need to make sure that you embed the views pushed on to the stack in a UINavigationController. You can do that by going to the "Editor" menu, selecting "Embed in" and then selecting "Navigation Controller".
Let me know if I didn't understand your question or if you can post more details.
Navigation bar will be the same in the app. You can hide it, show it, change title, change background color, or background image on each view depending on your requirements. But there is only one navigation bar in navigation based apps.

Should I use a tab bar or button at the bottom of my ViewController?

I'm just learning iOS, and I want to create an App which will have a few buttons at the bottom of the screen.
What I'm a bit unsure about is, I know you can use a tab bar down there, but is that what you should always use when you want a button at the bottom of the screen? or there's no need to use a tab bar, and you can just put a normal button down there?
According to apple's documentation, UITabBar is a control used for displaying views.
A tab bar is a control, usually appearing across the bottom of the screen in the context of a tab bar controller, for giving the user one-tap, modal access to a set of views in an app.
If your goal with this "button" is to display other views, then you should use UITabBar component.
But if you are just searching for a "usual button", then you should use UIButton component.
A tab bar is expected to allow the user to switch between, you know, tabs; the same bar appears at the bottom of each page, and it allows you to switch between them. If that describes what you are trying to accomplish, then it would be appropriate. If your button is meant for some different purpose, then a tab bar might be misleading.
A tab bar (class UITabBar) is usually part of a tab bar controller (class UITabBarController). A button (UIButton is simply a way to respond to a tap or other actions within the button.
You want to use a tab bar and tab bar controller when you need to switch between different views and view controllers in your application. For example the Music app on your iPhone has a tab bar controller that switches between Artist, Playlist, Album, etc. These are different screens, or screens that look the same but show your music organized in a different way.
If all you want is to respond to a button, for example to print out to the console or show a message to the user that says "Hey, you've tapped the button", then a UIButton is what you need.
Also, a UIButton can have many actions, Touch Up Inside is probably the one you are looking for. This one will ensure the button has an action called if the user began a tap on the button, and let go of their finger while still on top of the button.
To summarize things:
Use a UIButton if you simply want to respond to an action, and the most common action you will connect to the button is Touch Up Inside.
Use a UITabBarController to have a way to switch between different views and view controllers.

Tabbar not showing in ios application

i am making one iOS tabbar application in that i have put 4 different tabs and whenever i click on 1 st tab and load another view after clicking of the first tab. After that when i press back button then tabbar is not displaying .So that i want hint that how can i show that
back the tabbar when we move from one tab from another and yes how i can use consistent the tabbar in whole application can you just guys help me on this i am new to iOS development.
here i am put the screen shot ...
here first screen is this one..
when i tap the video button that are first in the view then another window open
which are as under and see the tabbar is not there...
when in video controller there is tabbar is there but i drag and connect to that then tabbar is disabled
Looking at your screen snapshots, do I correctly assume you're attempting to transition to the "Videos" scene by touching the big "Videos" button in the center of the "Home" scene (rather than touching the tab bar button at the bottom of the screen, which I assume works fine)? If that's the case, you need to have your button tell the view controller's tab bar controller that you want to change the index of the tab bar, and it takes care of it for you. You cannot do the transition using a segue (or at least not without a custom segue, which is even more complicated than the procedure I outline below). If you're changing the view some other way (e.g. using a standard segue or using presentViewController, pushViewController programmatically, etc.), your tab bar can disappear on you.
You later said:
when in video controller there is tabbar is there but i drag and connect to that then tabbar is disabled
Yes, that's true. You cannot use a segue from one of your big buttons to one of the tabs in your tab bar. (Or technically, if you wanted to use a segue, it would be a custom segue which would do something very much like my below code, though perhaps a tad more complicated.) So, rather than using a segue for your big button, you need to write an IBAction (connected to the big Videos button on the Home scene), that tells the tab bar to change its selection:
- (IBAction)clickedVideosButton:(id)sender
{
[self.tabBarController setSelectedIndex:1];
}
A couple of comments:
My answer was predicated on the assumption that your tab bar works as expected when you tap on the buttons of the tab bar, itself. If you tap the buttons at the bottom of the screen, do you transition to your other views correctly and preserve the tab bar? If so, my answer above should solve your issues in getting the big buttons to work. If not, though, then the problem rests elsewhere and you need to show us your code that might account for that (either you're something non-standard in the UITabBarControllerDelegate methods, or your viewDidLoad of the view is doing something nonstandard).
If I understand your user interface design right, you have the tab bar at the bottom as well as the big buttons in the middle, which presumably do the same thing. That is, no offense, a curious user interface design (duplicative buttons, requiring extra tap on a button, etc.). You might want to choose to either use either big buttons (in which you can retire the tab bar, eliminate the IBAction code I've provided above, and just use a nice simple navigation controller and push segues, for example), or just use the tab bar (and lose the home screen, lose the big buttons, etc.).
You also made reference to "press back button", and I don't see any "back" button on any of your screen snapshots. Do I infer that you have a navigation controller and you're doing a pushViewController or push segue somewhere? If you're doing something with back buttons, you might need to clarify your question further.

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