Do I have to allocate view when I make app without IB? - iphone

I want to make window based app without using IB.
I created MyViewController by allocating it.
Do I have to create view inside MyViewController also?
Without allocating it, app crashes.
For UITableViewController, UINavigationController,... I don't have to allocate view.
What is difference?
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
viewController = [[MyViewController alloc]init];
viewController.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
[self.window addSubview:viewController.view]; // app crashes here without allocating view explicitly
}

you should either allocate the view explicitly just as you shown in your code or implement "loadView" in your controller so that the view is created when it is first shown on screen.

MyViewController *_myViewController = [[MyViewController alloc]init];
UIView* myView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
_myViewController.view = myView
[myView release];
[self.window addSubview:myViewController.view];

Related

UINavigationController not working under ARC in iPhone

I have created a new project "Empty Application" template in Xcode 4.3, it is having only two classes AppDelegate.h & .m
I checked with ARC to use automatic reference count while creating the app.
I added two new files "RootViewController" & "NewProjectViewControllers".
I implemented code to set navigation controller as follows in AppDelegate
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
rootViewController = [[MainViewController alloc] init];
UINavigationController *navigation = [[UINavigationController alloc] initWithRootViewController:rootViewController];
[self.window addSubview:navigation.view];
self.window.backgroundColor = [UIColor whiteColor];
[self.window makeKeyAndVisible];
return YES;
}
and in hte home view (Root view controller) implemented as follows
- (void)viewDidLoad
{
[super viewDidLoad];
self.title = #"Projects";
UINavigationBar *navigationBar = [self.navigationController navigationBar];
[navigationBar setTintColor: [UIColor colorWithRed:10/255.0f green:21/255.0f blue:51/255.0f alpha:1.0f]];
//To set the customised bar item
UIButton *rightBarBtn = [UIButton buttonWithType:UIButtonTypeCustom];
[rightBarBtn setBackgroundImage:[UIImage imageNamed:#"plus_new.png"] forState:UIControlStateNormal];
rightBarBtn.frame=CGRectMake(0.0, 100.0, 30.0, 30.0);
[rightBarBtn addTarget:self action:#selector(addProject) forControlEvents:UIControlEventTouchUpInside];
UIBarButtonItem* rightBarItem = [[UIBarButtonItem alloc] initWithCustomView:rightBarBtn];
self.navigationItem.rightBarButtonItem = rightBarItem;
// Do any additional setup after loading the view from its nib.
}
- (void) addProject
{
NewProjViewController *editProject = [[NewProjViewController alloc] init];
[self.navigationController pushViewController:editProject animated:YES];
NSLog(#"xxxxxxxxxxxxxxx");
}
But since i used ARC the navigation may dealoc immediately and it doesn't work, All the actions in method works except push to the next view
if i do same thing with out ARC it works fine
How to resolve this issue..? Thanks in advance
In Your appdelegate appdidfinishlaunching method, you have not set
self.window.rootviewcontroller to navigationController. In fact you did not set any rootViewController to Window. Thats why it is not being shown. Please set it before you start to see your ViewController on the screen.
The UIWindow rootViewController property is new with iOS4.
The older technique was to use addSubview.
The new, recommended technique is to set rootViewController.
Try this:
NewProjViewController *editProject = [[NewProjViewController alloc]initWithNibName:#"NewProjViewController" bundle:[NSBundle mainBundle]];
[self.navigationController pushViewController:editProject animated:YES];
[editProject release];

UIWindow subview disappears after when application becomes active

So, I am trying to achieve having a fixed top banner on Application UIWindow and a working navigation of multiple view controllers. I know there are other ways of performing this but for my project requirements I need to use xibs.
The code below allows to achieve this:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.headerView = [[UIImageView alloc] init];
self.headerView.frame = CGRectMake(0.0f, 20.0f, 320.0f, 44.0f);
self.headerView.image = [UIImage imageNamed: #"header-banner-background.png"];
[self.window addSubview:self.headerView];
self.viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
self.window.rootViewController = navigationController;
[self.window makeKeyAndVisible];
return YES;
}
Then in each ViewController viewWillAppear method I have resized both self.view and self.navigationController.navigationBar.frame in order to show themselves below the banner:
self.navigationController.navigationBar.frame = CGRectMake(0, 64, 320, 44);
self.view.frame = CGRectMake(0, 64, 320, 396);
This is fine, works exactly the way I wanted.
But if the user presses the home button and the application resigns active, when it becomes active again the last viewController seen get's displayed but without the UIWindow banner, and the self.view and navigationBar are displayed on top.
Of course the current UIViewController viewWillAppear method is not called when the application returns active, but even if I put the resize code in another function and call it through a notification it does not work. But when the user presses a bar item and moves in the navigation stack, then everything works again and UIWindow displays the headerView.
Anyone understands why the UIWindow headerView disappears when application returns active?
EDIT 1: Possible solution?
#interface RootViewController ()
{
ViewController *viewController;
UINavigationController *navigationController;
}
#end
#implementation RootViewController
- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
if (self) {
// Custom initialization
viewController = [[ViewController alloc] initWithNibName:#"ViewController" bundle:nil];
navigationController = [[UINavigationController alloc] initWithRootViewController:viewController];
}
return self;
}
- (void)loadView
{
// Implement loadView to create a view hierarchy programmatically, without using a nib.
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 88)];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
[imageView setImage:[UIImage imageNamed:#"header"]];
[view addSubview:imageView];
navigationController.navigationBar.frame = CGRectMake(0, 44, 320, 44);
[view addSubview:navigationController.navigationBar];
self.view = view;
}
EDIT 2: Second possible solution, still not working
- (void)loadView
{
NSLog(#"loadView root");
// Implement loadView to create a view hierarchy programmatically, without using a nib.
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 88)];
UIImageView *imageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
[imageView setImage:[UIImage imageNamed:#"banner"]];
[view addSubview:imageView];
navigationController = [[UINavigationController alloc] init];
navigationController.navigationBar.frame = CGRectMake(0, 43, 320, 44);
[view addSubview:navigationController.navigationBar];
[self addChildViewController:navigationController];
self.view = view;
[self.view setBackgroundColor:[UIColor yellowColor]];
}
This is the result, which seems fine, without the push of the viewController1 (note the yellow background is from the rootViewController):
This instead is the result of adding:
- (void)viewDidLoad
{
viewController1 = [[ViewController1 alloc] initWithNibName:#"ViewController1" bundle:nil];
[navigationController pushViewController:viewController1 animated:YES];
}
The new view controller is not pushed (the background should be black) and the navigation bar has disappeared.
EDIT 3: Olloqui solution, still not working
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window setBackgroundColor:[UIColor redColor]];
UIView *bannerView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 44)];
[self.window addSubview:bannerView];
UIView *navigationView = [[UIView alloc] initWithFrame:CGRectMake(0, 44, 320, 416)];
ViewController1 *viewController1 = [[ViewController1 alloc] initWithNibName:#"ViewController1" bundle:nil];
self.navigationController = [[UINavigationController alloc] initWithRootViewController:viewController1];
self.navigationController.navigationBar.frame = CGRectMake(0, 0, 320, 44);
[navigationView addSubview:self.navigationController.navigationBar];
[self.window addSubview:navigationView];
self.window.rootViewController = self.navigationController;
self.window.autoresizesSubviews = YES;
[self.window makeKeyAndVisible];
return YES;
}
Result is I have only the banner, viewController1 is pushed but no navigation bar is displayed. I really need to figure this out, anyone has a different approach?
The window expects to have a root view controlled by its rootViewController property. When returning from the background the window only asks for the rootViewController to restore the appearance of that view controller's view. It doesn't ask all subviews to refresh.
To fix this I would create a new root view controller. This would have the banner and the navigation controller. That navigation controller would then hold your normal view controllers and manage the navigation. The banner will appear properly upon the app returning from the background. Your banner will be stationary while navigation occurs within the navigation controller.
Edit: I whipped up a little example program.
I started with a simple single view app template. I added two view controllers for the content. The just have labels for differentiation, and one has a button that loads the second view.
All the magic happens in the main view controller's viewDidLoad method:
- (void)viewDidLoad
{
[super viewDidLoad];
// Do any additional setup after loading the view, typically from a nib.
OneViewController *oneVC = [[OneViewController alloc] initWithNibName:#"OneViewController" bundle:nil];
self.navController = [[UINavigationController alloc]initWithRootViewController:oneVC];
self.navController.view.frame = CGRectMake(0.0, 64.0, 320.0, 416.0);
[self.view addSubview:self.navController.view];
[self addChildViewController:self.navController];
}
The nib for this view loads the image view for the banner.
The example project in on Bitbucket.
I have never tried it before but I would take a shot to create 2 views in the UIWindow, one for the banner and the other one for the navigation + content. Then, insert the navigationBar view in this second view, that will be sized properly. I am not sure if the navigation is going to try to take the full window are, but resizing the navigation controller on each viewWillAppear doesnt look a good solution to me. Try it and comment the result!
I think you can try to workaround this problem by adding the banner view to window.rootViewController.view like this:
[window.rootViewController.view addSubview:bannerView]
Ok, I really needed to solve this ASAP, therefore I opted for a solution I was lucky enough to find here. I still have to solve the management of the UITabBarController added on bottom but the rest seems to be working fine. Thanks everyone for help and additional hints.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window setBackgroundColor:[UIColor redColor]];
// Create a view for the banner add the banner to this view
UIImageView *bannerImageView = [[UIImageView alloc] initWithFrame:CGRectMake(0, 0, 320, 45)];
bannerImageView.image = [UIImage imageNamed:#"banner"];
// put this banner above the nav bar
UIView *bannerView = [[UIView alloc] initWithFrame:CGRectMake(0, -44, 320, 44)];
[bannerView addSubview:bannerImageView];
//add the tabBarController as a subview of the view
UITabBarController *tabBarController = [[UITabBarController alloc] init];
[tabBarController.view addSubview:bannerView];
// Move the root view to show status bar & banner
tabBarController.view.frame = CGRectMake(0, 20+44, 320, 480-20-44);
//add the modified logo view to window
[self.window addSubview:tabBarController.view];
ViewController1 *viewController1 = [[ViewController1 alloc] initWithNibName:#"ViewController1" bundle:nil];
UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:viewController1];
tabBarController.viewControllers = [NSArray arrayWithObjects:navigationController, nil];
//tabBarController.tabBar.hidden = YES;
[self.window setRootViewController:tabBarController];
[self.window makeKeyAndVisible];
return YES;
}

Creating a UITableViewController programmatically

This is what I tried. Nothing appears on the screen and none of the UITableView methods that you are supposed to implement are getting called.
-(void)loadView
{
UIView *view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] applicationFrame]];
self.view = view;
[view release];
}
- (void)viewDidLoad
{
[super viewDidLoad];
UITableViewController *TVC = [[[UITableViewController alloc]
initWithStyle:UITableViewStylePlain] autorelease];
CGRect cgRct = CGRectMake(0, 10, 320, 100);
UIView *newView = [[UIView alloc] initWithFrame:cgRct];
TVC.view = newView;
[newView release];
[self.view addSubview:TVC.view];
}
I've looked for good examples and tutorials on doing this programmatically but there are none.
What I am trying to achieve is a Table that doenst take up my who screen. Maybe 3/4 of my screen would be good.
Many Thanks
Code
The problem is that you're creating a UITableViewController, which is a UIViewController, and will expect to be on the nav stack. What you want to do is create a UITableView, which is a UIView. You are also not setting the table's delegate and data source, which you will need to do to get calbacks.
Your viewDidLoad should look something like this
- (void)viewDidLoad
{
[super viewDidLoad];
UITableView *table = [[[UITableView alloc] initWithStyle:UITableViewStylePlain] autorelease];
table.dataSource = self;
table.delegate = self;
table.frame = CGRectMake(0, 10, 320, 100);
[self.view addSubview:table];
}
(Note that if you're going to need access to the table outside of the callbacks, you should save it in an ivar rather than declaring it locally, and should retain it. Let me know if you need a few more lines of code to show you what I mean)
Make sure you set the delegate of TVC, with
TVC.delegate = self;
That's the reason why none of those methods are getting called. Also, make sure your class implements the UITableViewDelegate protocol by changing your interface declaration to
#interface YourViewController : UIViewController <UITableViewDelegate> {
//declare variables here
}
Also, equally important, don't set TVC.view, as this already happens when you initialize the view controller. You're just setting it to a blank view, which is why you're not seeing anything.
iOS7 seems to like this way of init'ing the tableview:
//make tableview
UITableView *table = [[UITableView alloc] initWithFrame:CGRectMake(0, 81, 200, 200) style:UITableViewStylePlain];
table.dataSource = self;
table.delegate = self;
[self.dataView addSubview:table];
try that out. Hope it helps someone.
UIView *newView = [[UIView alloc] initWithFrame:cgRct];
TVC.view = newView;
I'll give you a hint. Here you are setting the view of the UITableViewController to an EMPTY VIEW...

Proper way to release view in UIViewController

I am building my own view in loadView of view controller. Just to check if I can release the view like below or there is anything else I will need to release it? I know framework will set it to nil once it requires to free up some memory.
- (void)loadView
{
self.view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
[self.view release];
...
}
That looks a bit weird, I'd do this instead:
UIView *view = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)];
self.view = view;
[view release];
If you're using #property (retain) you don't have to worry about releasing it when it's set to nil e.g. self.view = nil;. However you should release it in dealloc.
The view property of a UIViewController will be released for you by the UIViewController itself. You are right however that when you create the view that you assign to a UIViewController you need to release it, but the way you are trying to do it is wrong. Either do what jtbandes suggest or simply:
self.view = [[[UIView alloc] initWithFrame:CGRectMake(0, 0, 200, 200)] autorelease];

How to get rid of gap when I add my custom UIViewController to window?

I'm getting this gap at the bottom of my window after I add the view of a custom UIViewController. The gap goes away as the view is shifted down after I move to another view and then back.
Here is the code in the app delegate:
- (void)applicationDidFinishLaunching:(UIApplication *)application {
// Override point for customization after application launch
CustomViewController *gvc = [[CustomViewController alloc] init];
self.customViewController = gvc;
[gvc release];
[window addSubview:customViewController.view];
[window makeKeyAndVisible];
}
"CustomViewController" is used as a root view controller to simply coordinate which other UIViewControllers to display. As such I simply set its view = to that of the first ViewController's view needed like so:
- (void)loadView {
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
self.view = v;
[v release];
// Add the HomeViewController to the top of the stack
MainViewController *mvc = [[MainViewController alloc] initWithNibName:#"MainView" bundle:nil];
mvc.delegate = self;
self.mainViewController = mvc;
[mvc release];
[self.view addSubview:self.mainViewController.view];
}
I've tried a bunch of things including what you see here with no luck. Any ideas?
thanks
This line
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 0, 320, 480)];
should be ...
UIView *v = [[UIView alloc] initWithFrame:CGRectMake(0, 20, 320, 460)];
Good times.