I have an application that uses the "navigation-based application" template in XCode.
Now I want to change it so that the first view that loads is a regular (custom) UIView, and if the user clicks a particular button, I push the original RootViewController onto the NavigationController.
I understand that somewhere, someone is calling this with my RootViewController:
- (id)initWithRootViewController:(UIViewController *)rootViewController
I want to know how to replace the argument with my new class.
if you want to replace the root view controller of your navigation stack you can replace the first object of its view controllers array as -
NSMutableArray *viewControllers = [NSMutableArray arrayWithArray:[self.navigationController viewControllers]];
NewViewController *nvc = [[NewViewController alloc] init];
[viewControllers replaceObjectAtIndex:0 withObject:nvc];
[self.navigationController setViewControllers:viewControllers];
^ These are all ways to do it programmatically. Thats cool. But I use the interface builder and storyboards in Xcode, so this is the easy and fast way to add a new view controller:
Open the storyboard in question
Add a new view controller to your storyboard by dragging it from the objects list (right hand tool bar bottom)
While holding down the CONTROL key, click and drag from the middle of your navigation controller (should be blank and gray) to your new fresh white view.
On the popup, selection Relation Segue: Root View Controller (should be below the normal push/modal/custom options you have likely seen before)
Tada! Enjoy your new root view controller without holding your day up with programmatic creation.
Look inside the main app delegate .m file and find the method
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
Inside it will be a line like this
self.window.rootViewController = self.navigationController;
You can instantiate a diffent view controller there and assign it to be the rootViewController
Related
I need the same type of table view controllers in my app many times and would like to create a more generic table view controller which I can use over and over again.
These table view controllers are quite simple and show only the contents of an array, put a check mark to the selected table view cell and return the index of the selected table view cell to the calling view controller after the Done button in the toolbar has been tapped.
Currently I create each one of these table view controllers directly in Storyboard and instantiate them by using segues.
Would it be possible to do this in code only (without using Storyboard or xibs)?
What would be the best way to instantiate and push them onto the navigation controller stack (each one will be shown in a view controller).
It's trivial to do this in code. You create your view controller class just like you normally would (extend UITableViewController). Implement all of the same table view data source and delegate methods. All of that is the same.
When you want to use the table view controller you just do:
MyTableViewController *vc = [[MyTableViewController alloc] init];
[self.navigationController pushViewController:vc animated:YES];
I would define your MyTableViewController init method like this:
- (id)init {
if ((self = [super initWithStyle:UITableViewStyleGrouped])) {
// any other initialization
}
return self;
}
BTW - I have an app with over 100 view controllers in it and I've never used Interface builder or storyboards. It's all code.
Would it be possible to do this in code only (without using Storyboard or xibs)?
Yes. Anything you can do in a storyboard or .xib file, you can do in code:
MyViewController *vc = [[MyViewController alloc] initWithNibName:nil bundle:nil];
Note: the default behavior for a view controller is to load its view from a .xib with the same name as the view controller's class when you pass nil for the .xib name, e.g. MyViewController.xib for the example above. So the line above creates the view controller in code, but will still load the view from the .xib. If you want the view created programmatically as well, override -loadView.
I'm trying to do a really simple thing - I've got a main Xib file for the whole app and another Xib file for a small view.
I want the small view (Xib called "additionalView.xib") to appear in the first Xib ("ViewController.xib").
I have succeeded to do so in the "ViewController.m" but I want more - I want to do it from "additionalView.m"
There is a method I created called "openView:" in "additionalView.m" and it looks like this:
-(IBAction)openView:(id)sender
{
ViewController *vc = [[ViewController alloc] init];
NSArray *nibObjects = [[NSBundle mainBundle] loadNibNamed:#"additionalView" owner:self options:nil];
UIView *nibView = [nibObjects objectAtIndex:0];
[vc.view addSubview:nibView];
}
The method is being called and the lines are being read by the debugger - but nothing happens.
No crash - No error - No small view in bigger view.
Why is that?
I know that the last line is probably what's
screwing everything up but i don't know how to put it correctly.
Your problem is that ViewController *vc = [[ViewController alloc] init]; creates a new view controller. Because it's new, it's not the one that already exists in the view controller hierarchy that's managing the display.
Your method needs to access the existing view controller. How it does that depends on your app's structure and which object has a reference to the original controller object.
Try
[self.view addView:view.vc];
However, I'm not sure what is you view structure here. You say your -(IBAction)openView:(id)sender is in your "additionalView.m", but it is not the main view controller, correct? You need to do this in the main controller, so basically move the openView: method to your ViewController.m
And you normally need a separate view controller for each view to keep things neat and separate, so the additionalView.m should be an instance of UIViewController, which you can then create from your main view as follows:
-(IBAction)openView:(id)sender
{
AdditionalView *vc = [[AdditionalView alloc] initWithNibName:#"additionalView"];
[self.view vc.view];
}
You have options ... First you don't need to create a view controller vc if you just need the view . Create a uiview and add it .
Option 1: pass a ref to the app vc as suggested above and then :
[appVC.view addsubview:additionalView]
This will add it to main.
Use a view controller manager / ref in the app delegate that you can refer to as delegate and add your view to the current showing view.
Hope this helps
I have made a very simple Navigation based app (UIViewController). The view has a single button on the Main RootViewController.
Next, I made 2 classes: TabOneViewController, TabTwoViewController. All good. I then created a new Class TabBarViewController. I opened up the NIB file and dropped on a ``UITabBarController onto it. The two tabs it creates in it by default were assigned (respectively) to my TabOne and TabTwo view controllers.
strong text
Then in my TabBarViewController, I made an IBOutlet for a UITabBarController, synthesized it etc etc. I linked it up in Interface builder via the "files owner".
In the RootViewController, I linked the button to my "pushView" method, and in this pushView method, I have the following code:
- (IBAction) pushView {
TabBarViewController *controller = [[TabBarViewController alloc] init];
[self.navigationController pushViewController:controller animated:YES];
[controller release];
}
The end result is it DOES push a view, but I cannot see the tab bar at the bottom, let alone any of the pages I've added to the controller.
What am I doing wrong? Why can't I link it in IB?
I am not 100% sure if that's allowed.. because you already have one tabBarController as rootViewController, and you dropped one more tabBarController as first tab controller, tabs ll overlap, considering amount of real estate you have on your iPhone, it make sense to not allow a tabViewController inside another
First, you need to allocate your view controller with your nib:
TabBarViewController *controller = [[TabBarViewController alloc] initWithNibName:#"YourNibName" bundle:nil];
Secondly, in IB, click the UITabBarController and go to the identity inspector and make sure you select your custom class. That said, unless you are overriding or adding some functionality you probably don't need the custom class at all, simply use a UITabBarController directly:
UITabBarController *controller = [[UITabBarController alloc] initWithNibName:#"YourNibName" bundle:nil];
My app has a map that tracks the user's location. This map will only appear under certain circumstances, and will dominate the user's attention until a particular task is complete, which is why the map isn't part of a navigation or tab bar UI.
If my map VC is set as the initial view controller in storyboard, it works fine. But if I try to load the map VC from elsewhere like this;
MapViewController *mapVC = [[MapViewController alloc] init];
[self presentModalViewController:mapVC animated:YES];
I just get a black screen.
I can confirm with NSLog that the VC is calling viewDidLoad and viewDidAppear, but the 'map' property of the VC is (null). I don't understand why (or how) I need to create the map property manually when using this technique, but it gets done for me when it is the initial VC.
The MapViewController instance in your storyboard is configured with a view hierarchy, including an MKMapView, and whatever else you did to configure that particular instance in the storyboard.
Now in this code which you show here, you are creating a completely new instance of MapViewController. It has no relationship to the instance in the storyboard other than they happen to be of the same class. So the one you create here with [[MapViewController alloc] init] has no view hierarchy (which is why you see a black screen), and none of the outlets or other configuration you may have made to the other MapViewController in your storyboard.
So what you want is to load that MapViewController that you've already set up from the storyboard. Assuming you are doing this from within a method in another view controller loaded from the same storyboard already, you can just do this:
// within some method on another vc from a scene in the same storyboard:
// given an identifier for the map view controller we want to load:
static NSString *mapVCIdentifier = #"SomeAppropriateIdentifier";
NSLog(#"Storyboard: %#",self.storyboard); // make sure this vc(self) was loaded from a storyboard
MapViewController *mapVC = [self.storyboard instantiateViewControllerWithIdentifier:mapVCIdentifier];
[self presentModalViewController:mapVC animated:YES];
And then back in the storyboard, just make sure you set the identifier for this map view controller to "SomeAppropriateIdentifier".
Hope that helps.
- i have a FirstViewController and a SecondViewController, each has its xib
- in the MainWindow.xib i have a UINavigationController, which is connected to IBOutlet
- in the AppsDelegate i call
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
FirstViewController * fv = [[FirstViewController alloc] init];
[navigationController pushViewController:fv animated:NO];
[fv release];
[self.window addSubview:navigationController.view];
[self.window makeKeyAndVisible];
return YES;
}
4) the problem is, when i want to manage Navigation item through interface builder... like for the first view i want to add a button to the right and customize the back text and the title
sure i could do this using code :
(by fv.navigationItem.rightBarButtonItem = ... and fv.title=#"...") but i want to achive this in interface builder
in my FirstViewController.xib and SecondViewController.xib i add a Navigation item and add the a right Bar item
the problem is, it never shows up and the title doesnt alter
if i open MainWindow.xib and add a ViewController (FirstViewController) under the NavigationController (so its listed under it = make it the rootViewController for the NavigationController) and also add Navigation item and Bar Buttom item, whoala, the NavigationBar at the top has the left button
again this would be great... BUT i cannot do the same think for the SecondViewController, because in interface builder, there can be only one rootViewController under the Navigation Controller... and again if i add the Navigation item in SecondViewController.xib it doesnt show up:(
- so ho can i manage the Navigation items and Bar button items for multiple ViewControllers in interface builder
(i looked at most tutorial, but they do it inside the code, by .navigationItem.rightBarButtonItem, what i want to avoid)
ok, the best solution i found
is to design the buttons in Interface builder and link them via Outlet, then in code i simply add them
fv.navigationItem.rightBarButtonItem = myOutletButton;
i didnt find a way to do it just only in interface builder so it gets bind automaticly :(
If u like to do a separate NVC please instaniate it not from main view, do this from different view's separate.