Adding UIImageView to rootViewController - ios

Question

All I am simply trying to do is display an image on the screen as I am just starting out iOS
development. I figured since UIImageView is a subclass of UIView, I would add it in a similar way but I am not having any luck. I understand this is an easy question but any help would be appreciated.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions: (NSDictionary *)launchOptions
{
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
self.window.rootViewController = [UIViewController new];
UIImage* stallion = [UIImage imageNamed:#"stallion1.png"];
UIImageView* iv = [UIImageView alloc];
iv.image = stallion;
[self.window.rootViewController.view addSubview:iv];
[self.window makeKeyAndVisible];
return YES;
}

Answer 1

Try something like this:
App delegate:
#import "RootViewController.h"
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
// Override point for customization after application launch.
//allocate and initialize the root view controller
RootViewController *rootViewController = [[RootViewController alloc] init];
//set the root view controller
self.window.rootViewController = rootViewController;
[self.window makeKeyAndVisible];
return YES;
}
Create a subclass of UIViewController called RootViewController
.h
#import <UIKit/UIKit.h>
//set the class RootViewController as a subcalss of UIViewController
#interface RootViewController : UIViewController
#end
.m
//this is one of the life cycle methods of a UIViewController and should already be in the code when the class is created
- (void)viewDidLoad
{
//execute the viewDidLoad method of the superclass (UIViewController)
[super viewDidLoad];
//allocate and initialize the image view
//assign the image view a frame
//x offset from the left = 0.0
//y offset from the top = 0.0
//width = the view controller's view's width (should be the whole screen)
//height = the view controller's view's height(should be the whole screen)
UIImageView *iv = [[UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, self.view.frame.size.width, self.view.frame.size.height)];
[iv setImage:[UIImage imageNamed:#"myImageName.png"]];
//the background will be red if everything is setup correctly, but the image isn't found
[iv setBackgroundColor:[UIColor redColor]];
//add the image view to the view controller's view
[self.view addSubview:iv];
}

Answer 2

//EDIT
It would be very helpful for you if u will read book in which there are information about View Controllers. This is very essential information. I recommend you to read "The Core IOS 6 Cookbook" by Erica Sadum. It really helped me.
You can also just look at the apple documentation http://developer.apple.com/library/ios/#documentation/WindowsViews/Conceptual/ViewControllerCatalog/
Write something like this in AppDelegate.m:
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
MyViewController *viewController = [[MyViewController alloc] init];
self.window.rootViewController = viewController;
[self.window makeKeyAndVisible];
return YES;
}
Next you must add the UIImageView but only when the view of the created view controller is loaded. The best method for this is viewDidLoad. You can also use viewDidAppear: or viewWillAppear:.
You must override this methods in MyViewController class (which should inherit from the UIViewController class).
- (void)viewDidLoad
{
[super viewDidLoad];
UIImageView *imageView = [UIImageView alloc] initWithFrame:CGRectMake(0.0, 0.0, self.frame.size.width, self.frame.size.heigth);
imageView.image = [UIImage imageNamed#"stallion1.png"];
[self.view addSubview:imageView];
}