Change main viewController - ios

I am using multiple viewcontrollers but need to change which who loads first. I have found some old tips but those are regarding .nib files and I belive those might not be up to date. Preferably I'd like to find some option in the menu's, as I frankly think this should be very simple.
Any ideas to a simple way of changing with viewController is loaded first?

Open the storyboard file
Display the document outline
Select the view controller that you want to be first
Under the "Attributes inspector", select "Is Initial View Controller"

You can programmatically load a view controller first through your AppDelegate.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window.rootViewContoller = <firstViewControllerIWantToLaunch>;
return YES;
}
This ensures that the view controller you want to load first is the root view controller, and will be the first view controller presented.

If you're using storyboard, select the view controller you'd like, and search for the "Is initial view controller" checkbox. I can't tell you where exactly it is, since I don't have Xcode open.
If you're using xibs, you need to change it in the AppDelegate applicationDidFinishLaunchingWithOptions method. (Refer to Bryan's answer for that.

If you want to switch between the two view controllers programmatically, Try doing Some thing Like this,
In your AppDelegate.m file in
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions.. Method
just place this condition..
If(loadFirstView){
UINavigationController *navController = (UINavigationController *)self.window.rootViewController;
FirstViewController *menu = [navController.storyboard instantiateViewControllerWithIdentifier:#"FIrstVC"];
navController.viewControllers = [NSArray arrayWithObjects:menu, nil];
[self.window makeKeyAndVisible];
}else{
UINavigationController *navController = (UINavigationController *)self.window.rootViewController;
SecondViewController *menu = [navController.storyboard instantiateViewControllerWithIdentifier:#"SecondVC"];
navController.viewControllers = [NSArray arrayWithObjects:menu, nil];
[self.window makeKeyAndVisible];
}
Don't Forget to assign StoryboardIDentifiers "FirstVC" and "SecondVC" in your storyboard file…This should do it, It works Well for me

As already answered here, you need to select your project's main storyboard file, select the main view controller, go to attributes inspector and, check the checkbox title "Is Initial View Controller" to make main view controller loading as first view controller upon app launch.

Related

Creating a UINavigationController for the first UIViewController

It seems there are several approaches to creating a UINavigationController to be the very first controller. Perhaps the easiest way is to simply click the View Controller in Storyboard and embed it in a navigation controller. But I would like to know the best approach when doing this only in code.
You can subclass UINavigationController, import the first view controller, and in viewDidLoad alloc and init an instance, then add it as a childViewController. In Storyboard replace the default view controller with a navigation controller and set the class to your nav controller. Note that in previous versions of iOS it was not recommended to subclass UINavigationController.
Or you can create another UIViewController, alloc init the first view controller, then alloc init a UINavigationController with that view controller as the root, add the navigation controller as a child view controller of this view controller, and add the navigation controller's view as a subview of this view controller's view. Change the class of the view controller in Storyboard. This is an awkward setup though, because you create a view controller whose purpose is to add a nav controller but it's not a nav controller itself.
I've read about another approach which involves creating the UINavigationController in the AppDelegate. Perhaps there are even more solutions.
What is the most appropriate approach, working in the latest development environment, targeting iOS 8+?
If you're starting with a controller in the storyboard, you only need to add two lines in the app delegate to embed that controller in a navigation controller. If you want to do it in code, I think this is the simplest way,
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:self.window.rootViewController];
self.window.rootViewController = nav;
return YES;
}
If you want to do it entirely in code, with no storyboard, then you need to create the window, the navigation controller, and its root view controller. You also need to click on the project icon in the files list, and in the "General" tab, delete the word "main" from the "Main Interface" pull down (that entry tells the system to start with a storyboard named "main.storyboard").
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
ViewController *vc = [ViewController new]; // You need to create this controller's view in its loadView method
vc.title = #"Root View Controller";
UINavigationController *nav = [[UINavigationController alloc] initWithRootViewController:vc];
[self.window setRootViewController:nav];
[self.window makeKeyAndVisible];
return YES;
}

How to programmatically show a controller that has a navigation controller and tabbar controller as defined in a storyboard?

I'd like to show the tableview controller embedded in the navigation controller from the app delegate.
The reason I need to do this is I'm building a wrapper over an api, so to login I direct users to a relevant webpage where they can login to grant my app access to their credentials, then they are sent to a relevant url end point which triggers my app. At this point I want to load the tableviewcontroller in the navigation and tabbarcontroller.
Is it possible to define multiple entry points on storyboards?
A screenshot of my current storyboard configuration is shown here:
https://www.dropbox.com/s/6wfo5werrs6vwy1/Screenshot%202014-10-09%2008.43.15.png?dl=0
You cannot define multiple entry points on storyboards. To achieve this, you should use [UIStoryboard instantiateViewControllerWithIdentifier:] and set the view controller to root view controller in your app delegate based on your condition.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
NSString *identifier
if (/* path A */){
identifier = #"vc1";
} else {
identifier = #"vc2";
}
UIViewController *vc = [storyboard instantiateViewControllerWithIdentifier:identifier];
self.window.rootViewController = vc;
[self.window makeKeyAndVisible];
}

Making your custom view controller to be the root IOS

I have a main view controller using a navigation controller and i was making my application over that. Now i want to add a welcome view controller for my app and make it show first instead of my main view controller. Is there any way to do it.
What I did was adding a view controller to my storyboard and added two classes of the same name then i made it my root view controller and unchecked the root view controller from the main view but it is not showing on the window. Please help me, that how can i make my welcome view to appear before the main view controller. Thanks
Inside Interface Builder, under the attributes section (looks like a small slider) about a quarter of the way down the list of settings, there is a section labeled "View Controller." The second item in that section is a checkbox "Is Initial View Controller," check that box and you should see the starting arrow of the story board move to the specified view controller and the app should launch to that page.
Hope this Helps.
You could do this programmatically by setting the app window's rootViewController. From the app delegate's application:didFinishLaunchingWithOptions:
- (BOOL)application:(UIApplication *)application
didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
UIScreen *mainScreen = [UIScreen mainScreen];
self.window = [[KTAppWindow alloc] initWithFrame:mainScreen.bounds];
[window makeKeyAndVisible];
window.rootViewController = [[WelcomeViewController alloc] init];
return YES;
}
Then you just need to set up your trigger to switch from the Welcome view to the main view. This could be scheduling an NSTimer, for example. Whatever the trigger is, once it occurs just change the window's rootViewController instance to your MainViewController.
I hope this helps.
It calls "Splash Screen" you just need to add a new ViewController in your Storyboard or if you don't have a Navigation Controller add.
In the Splash class, in the viewDidLoad method you need to put this:
UIStoryboard *sb = [UIStoryboard storyboardWithName:#"Main" bundle:nil];
HomeViewController *vc = [sb instantiateViewControllerWithIdentifier:#"Home"];
[[[[UIApplication sharedApplication] delegate] window] setRootViewController:vc];
[self performSegueWithIdentifier:#"Home" sender:self];
here you can add conditions if you needed

Can performSegueWithIdentifier be used with the AppDelegate?

I am working on an app that at launch checks for valid login credentials, and if they are found and not expired the main split view controller is displayed, and if not a login screen should be displayed.
Each part is working fine separately, but I am struggling with the best way at launch time to select the proper view to display.
I have tried setting up a modal segue from the root view controller, and in my application:didFinishLaunchingWithOptions: function in the App Delegate, calling this:
// Segue to the login view controller...
if (loginNeeded) {
[self.window.rootViewController performSegueWithIdentifier:#"LoginScreen" sender:self];
}
This logically should work, but triggering segues from within the app delegate seems to be impossible.
What is the ideal place and technique for handling this?
You could try a custom segue, as per this post hiding-a-segue-on-login-process.
Alternatively if you're desperate to have the login display before the split view controller loads try something along the following lines...
Create your login screen on the main storyboard as, say, a subclass of UIViewController. Make sure it is the initial scene (check Is Initial View Controller).
On the storyboard, create a new segue from your login class to the original SplitViewController. Give it an identifier, 'Load SplitViewController' and a segue custom class name which we'll call FullyReplaceSegue.
In your login class .m file, add code to be called once the user has logged in:
[self performSegueWithIdentifier:#"Load SplitViewController" sender:self];
Create the new segue class, based on UIStoryboardSegue and name it FullyReplaceSegue as per above.
.h file
#import <UIKit/UIKit.h>
#interface : UIStoryboardSegue
#end
.m file
#import "FullyReplaceSegue.h"
#implementation FullyReplaceSegue
- (void)perform
{
UIViewController *dest = (UIViewController *) super.destinationViewController;
UIWindow *window = [UIApplication sharedApplication].keyWindow;
window.rootViewController = dest;
if ([[UIDevice currentDevice] userInterfaceIdiom] == UIUserInterfaceIdiomPad) {
UISplitViewController *splitViewController = (UISplitViewController *)dest; // assumes we're transitioning to a UISplitViewController!
UINavigationController *navigationController = [splitViewController.viewControllers lastObject];
splitViewController.delegate = (id)navigationController.topViewController;
}
}
#end
Here's how I did it.
In didFinishLaunchingWithOptions:
//save the root view controller
[[self window] makeKeyAndVisible];
UINavigationController *navigationController = (UINavigationController*) self.window.rootViewController;
rootController = [[navigationController viewControllers] objectAtIndex:0];
Somewhere else in the app delegate:
[rootController performSegueWithIdentifier:#"fileSegueID" sender:self];
Then, in the storyboard, create a segue from the view that gets assigned as "rootController", to the desired optional view, and give that new segue the id fileSegueID. It takes some debugging to make sure the rootController variable gets assigned to the correct view.
Maybe a little late, but I was looking for the same suggestions. Here's what I wound up doing.
UIStoryboard *storyboard = [UIStoryboard storyboardWithName:#"Signup" bundle:nil];
if(isLoggedIn) {
UINavigationController *navigationController = (UINavigationController*) self.window.rootViewController;
IndexController *ivc = [storyboard instantiateViewControllerWithIdentifier:#"IndexController"];
[navigationController pushViewController:ivc animated:NO];
}
Why don't you load the screen that would be visible assuming proper and non-expired log-in credentials (by setting it as the root view controller of the window), and then in viewDidLoad of that first view controller, check if an update to the login credentials are needed. If so, segue into the login view controller.
Yes, it can be used, if you get a reference to the segue's parent view controller. You can get it like this:
UINavigationController *navigationController = (UINavigationController*) self.window.rootViewController;
[[[navigationController viewControllers] objectAtIndex:0] performSegueWithIdentifier:#"LoginScreen" sender:self];
This will only work if the index in viewControllers array matches the one of your view controller and if it exists of course. In this case is the first one (in the array and storyboard).
The segue ("LoginScreen") must not be attached to an action. The way you do this is by control-dragging from the file owner icon at the bottom of the storyboard scene to the destination scene. A popup will appear that will ask for an option in “Manual Segue”; pick “Push” as the type. Tap on the little square and make sure you’re in the Attributes Inspector. Give it an identifier which you will use to refer to it in code.

Navigation Controller is null

I have a split-view app that allows a user to select and display a thumbnail of a chosen image. I have placed a UIButton in the detailViewController using Interface Builder. When this button is pressed, I would like to have it change to a full screen view of the image. I have set up a new View Controller, called FullViewController and thought I had everything connected. The problem is that the navigation controller is null. I adjusted the AppDelegate.m to the following:
AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after app launch.
// Set the split view controller as the window's root view controller and display.
self.window.rootViewController = self.splitViewController;
UINavigationController *nvcontrol =[[UINavigationController alloc] initWithRootViewController:fullViewController];
[window addSubview:nvcontrol.view];
[self.window makeKeyAndVisible];
return YES;
}
This is the function in the DetailViewController.m which is called when the button is pressed. The navigation controller comes up null in here.
//Function called when button is pressed - should bring up full screen view
- (IBAction) pressFullViewButtonFunction: (id) sender{
//viewLabel.text = #"Full View";
if (fullViewController == nil){
FullViewController *fullViewController = [[FullViewController alloc] initWithNibName:#"FullViewController" bundle:[NSBundle mainBundle]];
NSLog(#"fullViewController is %#", fullViewController);
self.fullViewController = fullViewController;
}
NSLog(#"self.navigationController is %#",self.navigationController);//this is null
[self.navigationController pushViewController:self.fullViewController animated:YES];
}
I'm not sure how to fix this. I've tried adding in the couple lines in the AppDelegate, but when it runs, the table in the root view doesn't show up and it no longer properly switches between portrait and landscape views.
I have the rest of the code readily available if that would help clarify. Just let me know!
Thanks.
From the code you post it is not possible to identify the problem, but two common reasons for self.navigationController to be nil are:
you did not push the object behind self on to the navigation controller in the first place; indeed it seems so, since the navigation controller is added as a subview of the split view controller; possibly you mean the opposite... not sure...
(sub-case of 1) you showed the object behind self using presentViewControllerModally.
When I say "the object behind self" I mean the instance of the class where pressFullViewButtonFunction is defined.
If you need more help, post the code where you push your controllers on to the navigation controller...
On a side note, if you do:
UINavigationController *nvcontrol =[[UINavigationController alloc] initWithRootViewController:fullViewController];
and nvcontrol is not an ivar, then you have a leak.
Hope this helps...

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