self.window.rootViewController = self.tabBarController;
[self.window addSubview:self.tabBarController.view];
They are used in the context below:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// Override point for customization after application launch.
// Add the tab bar controller's current view as a subview of the window
// self.window.rootViewController = self.tabBarController;
[self.window addSubview:self.tabBarController.view];
IntroViewController *introViewController = [[IntroViewController alloc] initWithNibName:#"IntroViewController" bundle:nil];
//Lets place introViewController in navController
UINavigationController * navController = [[UINavigationController alloc] initWithRootViewController:introViewController];
//Now lets display it
[self.tabBarController presentModalViewController:navController animated:YES];
[navController release];
[introViewController release];
[self.window makeKeyAndVisible];
return YES;
}
From iOS Reference:
rootViewController
The root view controller provides the content view of the window.
Assigning a view controller to this property (either programmatically
or using Interface Builder) installs the view controller’s view as the
content view of the window. If the window has an existing view
hierarchy, the old views are removed before the new ones are
installed.
addSubview
This method retains view and sets its next responder to the receiver,
which is its new superview.
Views can have only one superview. If view already has a superview and
that view is not the receiver, this method removes the previous
superview before making the receiver its new superview.
So we can say that the main difference is that setting rootViewController destroys all the previous views contained in the UIWindow, and using addSubView: only adds an UIView on top.
self.window.rootViewController = self.tabBarController;
This statement is wrong because window is a container you don't have any root controller there.
SubView:
[self.window addSubview:self.tabBarController.view];
Here you are adding the tabBarController as a subview which will add your windows container. And this is the right way to create the tab bar controller.
Related
current version of my project :
I have 5 different UIViewControllers in my app. I've set my
FirstViewController to be the Initial View Controller using the
Attributes Inspector. I move back and forth from one ViewController to
another by using buttons to which I assign modal segues, from one
ViewController to another, using the StoryBoard
What I want to change:
I want to keep the navigation buttons obviously, delete the modal segues and use
a UINavigationController instead. If I understand the concept
correctly, when using a UINavigationController I need to go into each
UIButton-IBAction and at the very end of the method I have to push the next
ViewController I want to move to, onto my NavigationController (do I also
have to pop the current one first?). However, I can't figure out how
to implement all that correctly.
What I've done so far:
I removed all modal segues from the storyboard and kept the navigation buttons along with their corresponding IBActions
I unchecked the box in the Attributes Inspector that was making my FirstViewController the initial View Controller of my app
I went into my AppDelegate.m and tried to create the Navigation Controller there and make my FirstViewController be the RootViewController
MyAppDelegate.m
-(BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
UIViewController *myFirstViewController = [[FirstViewController alloc] init];
UINavigationController *myNavigationController = [[UINavigationController alloc] initWithRootViewController:myFirstViewController];
[myNavigationController pushViewController:myFirstViewController animated:YES];
// Override point for customization after application launch.
return YES;
}
I then tried to test if the above was working by going into the IBAction of a
navigation button on my FirstViewController and implemented the
following in order to move to my SecondViewController when the
button is pressed :
FirstViewController.m
- (IBAction)goRightButton:(UIButton *)sender
{
// some code drawing the ButtonIsPressed UIImageView on the current View Controller
UIViewController *mySecondViewController = [[SecondViewController alloc] init];
[self.navigationController pushViewController:mySecondViewController animated:YES];
}
but nothing happens. What am I doing wrong ?
You are not linking your XIB file. Please add your navigation controller as
UIViewController *myFirstViewController = [[FirstViewController alloc] initWithNibName:#"FirstViewController" bundle:nil];
navigationController = [[UINavigationController alloc] initWithRootViewController:myFirstViewController];
Use following code to move from one view to another
UIViewController *mySecondViewController = [[SecondViewController alloc] initWithNibName:#"SecondViewController" bundle:nil];
[self.navigationController pushViewController:mySecondViewController animated:YES];
If you are using a storyboard, you should just drag in the navigation controller there and hook it up to your app delegates. As long as it is the main storyboard, and you have identified a view controller to load first, you do not need to load any views in your app delegate.
In order to push a view programmatically that's in a storyboard, you need to do something like the following:
//bundle can be nil if in main bundle, which is default
UIStoryboard *mainStoryboard = [UIStoryboard storyboardWithName:#"MainStoryboard" bundle:nil];
MyCustomViewController *customVC = (MyCustomViewController *)[mainStoryboard instantiateViewControllerWithIdentifier:#"customVC"];
//standard way
[self.navigationController pushViewController:customVC animated:YES];
//custom animation
[UIView transitionWithView:self.navigationController.view duration:0.5 options:UIViewAnimationOptionTransitionCurlUp animations:^{
[self.navigationController pushViewController:customVC animated:NO];
} completion:nil];
You identify the view controller with the identifier you add in the storyboard editor. Below are some screenshots to help show what I mean.
Supposed you've got:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
UIViewController *rootViewController = [[UIViewController alloc] init];
rootViewController.view.backgroundColor = [UIColor whiteColor];
[self.window setRootViewController:rootViewController];
[self.window makeKeyAndVisible];
UINavigationController *modal = [[UINavigationController alloc] initWithRootViewController:[[PTFrontViewController alloc] init]];
modal.modalPresentationStyle = UIModalPresentationFormSheet;
[rootViewController presentViewController:modal animated:YES completion:NULL];
return YES;
}
whereas PTFrontViewController and PTBackViewController view controllers have nothing interesting for sake of this example.
How could you push an instance of PTBackViewController from PTFrontViewController animating as in UIViewAnimationTransitionFlipFromLeft or UIViewAnimationTransitionFlipFromRight?
I am already well aware of these three things:
this is not exactly how you should make use of presentViewController
there is a good reason for UINavigationController's default animation
there are several answers how to "customize" UINavigationController's default animation while pushing and poping, but if you try the code for your self you will notice that when a view controller is presented via presentViewController there are drop shadows and background views that won't get animated correctly
So please answer taking these things in mind. Thank you.
First - forget UINavigationController. If you don't need the default animation, just put a UINavigationBar into your controllers. It will get a little easier.
Second - this is a difficult problem, you can't create such an animation only within the modal controller because the background wouldn't be repainted.
Sincerely, the easist solution I see is too forget the modal controller and just add the view controller as a child of your root controller. Then you can control all the animations but you have to write everything by yourself (including the background fading).
I've got a UITabBarController which contains a UINavigationController. Within the visible UIViewController, I'm creating a UITableView programatically as follows:
self.voucherTableView = [[UITableView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame] style:UITableViewStylePlain];
self.voucherTableView.autoresizingMask = UIViewAutoresizingFlexibleHeight|UIViewAutoresizingFlexibleWidth;
However, the UITabBar is overlapping the UITableView.
When I output the height of the [[UIScreen mainScreen] applicationFrame], it returns 460.00 whereas it should be 367.00.
In Interface Builder, I'm using the 'Simulated Metrics' which automatically sets the height of the view to 367.00.
Is there something I'm missing, no matter what I try I can't see to get the 367.00 height that I need.
As a temp fix, I've set the frame of the UITableView manually, this isn't really ideal so it would be nice to work out why this isn't working:
self.voucherTableView = [[UITableView alloc] initWithFrame:CGRectMake(0, 0, 320, 367) style:UITableViewStylePlain];
You should use self.view.bounds rather than [[UIScreen mainScreen] applicationFrame] as the last one returns you the whole screen frame while self.view.bounds provides you with your view bounds wich seems what you are searching for.
You should add the UINavigationController instance to the UITabBarController and then add a table view controller to the rootViewController property of the UINavigationController instance which should make your life a lot easier.
As a simple example of this, create an empty window-based application (the templates make this a lot more confusing than it really is).
Add your UIViewController/UITableViewController subclasses to the project then use this code as a guide to setting up your project. This code is in your AppDelegate class:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
// create our table view controller that will display our store list
StoresViewController *storeListController = [[StoresViewController alloc] init];
// create the navigation controller that will hold our store list and detail view controllers and set the store list as the root view controller
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:storeListController];
[navController.tabBarItem setTitle:#"TableView"];
[navController.tabBarItem setImage:[UIImage imageNamed:#"cart.png"]];
// create our browser view controller
BrowserViewController *webBrowserController = [[BrowserViewController alloc] init];
[webBrowserController.tabBarItem setTitle:#"WebView"];
[webBrowserController.tabBarItem setImage:[UIImage imageNamed:#"web.png"]];
// add our view controllers to an array, which will retain them
NSArray *viewControllers = [NSArray arrayWithObjects:navController, webBrowserController, nil];
// release these since they are now retained
[navController release];
[storeListController release];
[webBrowserController release];
// add our array of controllers to the tab bar controller
UITabBarController *tabBarController = [[UITabBarController alloc] init];
[tabBarController setViewControllers:viewControllers];
// set the tab bar controller as our root view controller
[self.window setRootViewController:tabBarController];
// we can release this now since the window is retaining it
[tabBarController release];
[self.window makeKeyAndVisible];
return YES;
}
In the code sample above the BrowserViewController is a subclass of UIViewController and the StoresViewController class is a subclass of UITableViewController. The UITabBarController and UINavigationController instances are created programmatically and added to the window.
By subclassing the UITableViewController class you avoid having to create a UITableView instance programmatically and get most everything you need out of the box.
When you need to push a detail view onto the UINavigationController instance's stack, you just have use something similar to this:
[self.navigationController pushViewController:YourDetailViewControllerInstance animated:YES];
This will add the detail view UIViewController subclass to the UINavigationController instance's view hierarchy for you and animate the transition.
Lots of controllers in this, but it's totally worth it and will avoid a lot of the problems you're experiencing as this method allows the views to manage resizing and take toolbars/navigation bars into account all by themselves.
I have a UINavigationController setup in my AppDelegate:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Add the navigation controller's view to the window and display.
[self.window addSubview:navigationController.view];
[self.window makeKeyAndVisible];
return YES;
}
In my RootViewController I am pushing another view onto the stack:
//Show the deals
DealViewController *dvc = [[DealViewController alloc] initWithNibName:#"DealViewController" bundle:nil];
[self.navigationController.navigationBar setHidden:NO];
[self.navigationController pushViewController:dvc animated:YES];
The view shows up, but there is no back button that is added to my navigation bar. Why is this and how can I resolve it?
Are you setting self.title in RootViewController? Perhaps the UINavigationController doesn't have any text to put on the back button, so it omits it...?
Are you setting hidesBackButton = YES or backBarButtonItem = nil in DealViewController, or does it have a different leftBarButtonItem defined?
Try this:
DetailViewController *detailViewController = [[DetailViewController alloc] init];
UIBarButtonItem *back = [[UIBarButtonItem alloc] initWithTitle : #"Back"
style : UIBarButtonItemStyleDone
target : nil
action : nil];
self.navigationItem.backBarButtonItem = back;
[self.navigationController pushViewController : detailViewController animated : YES];
[detailViewController release];
You must think of the navigation controller as a stack of navigation controllers each controlling one screen full of information.
You instantiate the navigation controller with the
-(id)initWithRootViewController:(UIViewController *)rootViewController
method. You specify the root view controller in this call. Then you add the navigation controller's view as a subview to the window, like you did before.
If you want to show your second screen you push another view controller on the stack by using
-(void)pushViewController:detailViewController animated:YES
method.
Using presentModalViewController to show the naviagtionController. Set the navagitionController bar button like so:
[navigationController.navigationBar.topItem setLeftBarButtonItem:
[[[UIBarButtonItem alloc] initWithTitle: #"Back"
style: UIBarButtonItemStylePlain
target: self
action: #selector(dismisstheModal:)] autorelease]];
This happened to me because in my navigation controller's content controller I had set up some navigation controller behavior in viewDidLoad and in another class that inherits from my content controller, and the one that was being presented, i implemented a viewDidLoad as well, and forgot to call [super viewDidLoad] which thereby caused me to override the base class's viewDidLoad where I was setting up my navigation controller buttons. Oooops.
I want to place two views side by side like they did in the MAIL app for the ipad. Is this possible with UINavigationController?
I would like to place two UINavigationController side by side
Dont worry about the syntax I just want to know if it is possible
UINavigationConroller *left;
UINavigationController *right;
[WIndow addSubView: left];
[WIndow addSubView:right];
UIWindow inherits directly from UIView, so it is possible to add multiple objects to it, though if you add multiple view controllers then only one of them will receive rotation events.
The correct means to do a Mail-type presentation is to use a UISplitViewController, which automatically handles the transition between two view and one view mode. The Xcode template for a 'Split View-based Application' will even set you up so that you have an button to view the left tableview as a UIPopoverController if you're in portrait.
EDIT: example code, with a split view controller:
// a tiny little method to vend a new navigation controller; following Cocoa patterns, because it
// has 'new' in the name it vends an owning reference (ie, not autoreleased, retain count +1)
- (UINavigationController *)newController
{
UITabBarController *tabBar = [[UITabBarController alloc] init];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:tabBar];
[tabBar release];
return navController;
}
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
// generate a split view controller
UISplitViewController *splitView = [[UISplitViewController alloc] init];
// grab a couple of navigation controllers
UINavigationController *navController1 = [self newController];
UINavigationController *navController2 = [self newController];
// add the navigation controllers to the split view controller
splitView.viewControllers = [NSArray arrayWithObjects:navController1, navController2, nil];
[navController1 release];
[navController2 release];
// and put the whole thing on screen
[window addSubview:splitView.view];
[window makeKeyAndVisible];
return YES;
}