I am creating an app which has five screens, and each screen has a button called "Home Button".
When the user presses the home button, the user should go back to very first screen.
How can I do this?
I am adding each screen over another screen like this:
[self.view addSubview:myview];
UINavigationController has an array viewControllers of pushed viewControllers.
You can manipulate this array instead of pop commands.
You should have used an existing controller to manage your hierarchy between your views. But anyway, I think what you can do is calling removeFromSuperview on each subview and adding again your very first view. You can do this with :
[self.view.subviews makeObjectPerformSelector:#selector(removeFromSuperview)];
Or you can also tag the views as you add them, and remove only the tagged views to avoid removing your first view from superview.
Related
I have an app I am working on that has a main screen with two buttons. One will take you to a view of a GPS (map) and then once there (new VC) it has options for setting that position or bringing up a list (tableview, another VC) of all locations already tagged.
At the list VC, if you click on the table cell, it will bring up the VC with the map. Problem is, this then adds the same VC bak on the stack. If a user clicks the Cancel button, they go back ones screen, then cancel goes back another screen, etc... until back to the main.
I know I can do the [self.navigationController popToRootViewControllerAnimated:YES]; to pop back to root but that is not always what I want.
Also, I know I can do: [[[self presentingViewController] presentingViewController] dismissModalViewControllerAnimated:YES];
I guess what I am saying is I want to "reuse" the GPS map view so I can call it from other VC's, so that is why I didn't go with the "pass back" to calling VC. So, is there away to either when a button is pressed and is to present a new VC, can I dismiss the prior one after the new one is shown? This way, a dismiss of current VC would take me back to where I need to be.
I hope makes sense and also that this question doesn't fall into the "Not an actual question" category.
Any help or better suggestions is greatly appreciated. Thx
Geo...
If you want to jump back some number of levels in a navigation controller's VC stack, you'll probably want to use its popToViewController:animated: method. To figure out if a particular view controller is on that stack, look at the navigation controller's viewControllers property. Be careful, though, as this kind of jumping around is a rather nonstandard UI behavior (even though there's API for it) which might confuse your users.
Also, using navigation controllers and presenting modally aren't the only ways to manage multiple view controllers -- you can always set the window's rootViewController yourself (and animate the change with UIView animations), even wrapping up your custom transition type in a custom UIStoryboardSegue if you like.
You can put a delegate in the table view. So that when a cell is pressed the info is passed to the delegate method in the VC which will dismiss the table view and reloads itself with the new info. You will have to implement refresh method in that VC.
In my app, I would like a loading screen which has a start button, and when the user presses the start button, it displays my the actual parts of my application.
I can't use a Default.png because i need the functionality of the start button. And since my rootViewController is a tabBar, I can't simply add my screen as a subview, because then my loading screen just appears in each individual tab.
Any ideas?
You could create a new view controller and set that view controller as the root view controller. In the new view controller, create a UIImageView with the loading image and a UIButton where you want it. Then you could go in the storyboards and make the button transition to the "actual parts of [your] application".
Hope this helps!
There are several ways to do it. Assuming your app spends very little time in the Start Screen, I would implement it as a modal view controller that I display over the root tab view.
After you load your root tab bar view for the first time, present the Start Screen view controller without animations.
[tabBarViewController presentViewController:startViewController animated:NO completion:NULL];
If you do this early enough (e.g., in your app delegate's didFinishLaunching: method), the start screen will be the first thing the user sees. It's hard to say exactly where you should insert this code since you haven't said whether you are using storyboards or a default nib or loading a view manually etc.
When the button is pressed, simply dismiss the startViewController.
I've set up a really simple project using storyboards including two views as shown here: http://i.stack.imgur.com/iRx21.png. The navigation can be done by either selecting a cell in the custom table view or hitting the back button labelled with "<<". Everything works fine except the following:
when I switch between the views, every time an instantiation happens. The profiling shows an increasing number of view objects. I would like to keep only one of each view and instantiation should be happen only once. What am I doing wrong? (I'm using ARC.)
Thanks in advance!
You should not link your back button to the parent view controller. This is what causes the new instantiation.
The way to go is to embed the table view into UINavigationController (in IB, choose Editor -> Imbed In -> Navigation Controller. Then change your segue to a Push segue. You can of course hide the navigation bar etc. to make things look exactly as you like. Then, link the back button to the controller with an IBAction and in the handler do a simple
[self.navigationController popViewControllerAnimated:YES];
This would be the appropriate logic of what you are doing. Of course, you can also push the web view modally and then handle the button click with
[self dismissModalViewControllerAnimated:YES];
Hi there and thank you in advice for your help. I have a really strange problem while working with ViewControllers in Xcode4. First of all I have to say that I'm not using storyboards and I prefer to create any UI element programmatically. So I've set a UIButton and I want that, when pressed, it brings me to a new view controller. This is the code I'm using for a button:
-(void)settingsAndExportHandle:(UIButton *)buttonSender {
SettingsViewController* settingView = [[SettingsViewController alloc] initWithNibName:#"SettingsViewController" bundle:nil];
settingView.modalTransitionStyle = UIModalTransitionStyleFlipHorizontal;
[self presentModalViewController:settingView animated:YES];
}
This buttons is initialized and allocated in the viewDidLoad method of the RootViewController. I want to switch to the other view controller (in this case SettingsViewController) when I press the button.
The strange thing is that when I press the button, the animation that flips the controllers goes well, but when it finishes I obtain the EXACT same things that I had on the RootViewControllers (same custom views, same buttons, same all!). The question is: what I'm missing?? I have to say that I use ARC (automatic reference counting) so I can't release or dealloc the views and buttons I've created on my RootViewController.
Any help will be appreciated. Thank you all!
Pushing and and modally presenting view controllers does not deallocate the view controller that presented them. It simply adds the additional view controller to the stack. You'll need to implement a callback method so that when the user hits the button to flip back to root view controller, your settings view controller lets the root view controller know what's about to happen so you can call a method you've written to reset the interface back to whatever state you need it at. You may also be able to use viewWillAppear: but that's a little messy.
However, according to the Apple Human Interface Guidelines, the user expects that when they push a view controller or modally present it, the view controller they were on will save state and be exactly the way they left it when they came back. It's disconcerting and annoying when state is not preserved while in a navigation controller context. It is especially annoying when it's modally presented.
Think about this - A user is in a hypothetical Mail app. They start typing out an email and set a font size and a color. They tap on the add attachment button, which brings up a modal view controller that allows them to select a picture. They select the picture and the modal view is dismissed, and in your implementation, the mail composing interface would have reset and the email content would be gone or at the very least the selected font size and color would be back to the default. That's not a good experience.
I currently have a Main Window set up as a UINavigationController (also is the root view controller), and I have two views. The first view is the login screen, and the second screen is a table view screen. What I would like to have happen is to show different UIBarButtonItems based on what screen is showing up. For instance, when the logon screen is being displayed, I want a left button on the navigation bar to be displayed (more specifically, it'd be a Settings button before logging in). Once the user logs in, I want the left button to say "Logout" and the right to be a reload button. I've tried programmatically adding the buttons, but they won't show up. Any suggestions?
Also, I've gotten most of this done in IB, but I feel like it would probably be easier to add these buttons programmatically.
All subclasses of UIViewController have a property called navigationItem. While it is readonly, you can alter its properties. So in LoginViewController, you would do self.navigationItem.leftBarButtonItem = /* Code to create the bar button */ and likewise within the TableViewController. Let me know if you need more detail.