问题
Im having some troubles to start an iOS app using xibs instead of storyboard. The problem is that im getting a black screen and the first view controller is not being called (added break point to viewDidLoad method).
In the app delegate header i have declared this:
@property (strong, nonatomic) UIWindow window;
@property (strong, nonatomic) ViewController *viewController;
And in the didFinishLaunchingWithOptions method i have this implementation:
self.viewController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
navController.navigationBarHidden = YES;
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
Looking over some forums i found that i should be allocing the window so i added this as the first line of the function
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
The problem is that, when i do this, the app crashes after returning from didFinishLaunchingWithOptions method (SIGABRT without any trace).
I also tried to make the navController a property and also instantiating a default UIViewController class initing the same xib
What am i doing wrong?
Thanks and regards
回答1:
Hope this helps you:
Delete the view controller and storyboard file and new viewController.h,viewController.h.m ,viewController.xib file.
#import "AppDelegate.h"
@interface AppDelegate ()
@end
@implementation AppDelegate
@synthesize viewCOntrollerobj;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.viewCOntrollerobj = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:self.viewCOntrollerobj];
//navController.navigationBarHidden = YES;
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
return YES;
}
回答2:
Leave main interface empty
Add new ViewController.xib to the project and mark its file's owner class as "ViewController"
In AppDelegate.m
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; NSArray* xibContents = [[NSBundle mainBundle] loadNibNamed:@"ViewController" owner:nil options:nil]; ViewController* vc = [xibContents objectAtIndex:0]; UINavigationController *navigationController = [[UINavigationController alloc] initWithRootViewController:vc]; self.window.rootViewController = navigationController; [self.window makeKeyAndVisible]; return YES;}
build and run
回答3:
OK, at last i got it.
What i had to do is just add again
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
After this, just delete the .h, .m and .xib and create them again.
For any reason its working fine now.
回答4:
I didnt try with XIB, but this thing is working fine here:::
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
self.viewController = [[ViewController alloc] init];
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
navController.navigationBarHidden = YES;
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
// Override point for customization after application launch.
return YES;
}
and in ViewController's viewDidLoad
- (void)viewDidLoad {
[super viewDidLoad];
[self.view setBackgroundColor:[UIColor greenColor]];
// Do any additional setup after loading the view, typically from a nib.
}
And the green color comes on the screen.
Initialize the window before setting the root view controller for the window.
That's the only problem that i see in you code, as the rootViewController is set to a nil window, and after that you are initializing.
回答5:
To change your project to use xibs instead of storyboards start by creating a xib for each view controller. You will need to change the File's Owner to class to the view controller you are creating the xib for. Then link the File's Owner view outlet to the view in the xib.
After that, select your app target and change the Main Interface drop down to be empty. Now you can delete the storyboard file.
Finally, initialize your window in the app delegate's application:didFinishLaunchingWithOptions: method and set your initial view controller as the root view controller of the window. Then call makeKeyAndVisible on your app delegate's window and you should be good to go.
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
self.window = [UIWindow new];
self.window.rootViewController = [ViewController new];
[self.window makeKeyAndVisible];
return YES;
}
回答6:
In Swift 3.0
//MARK: Initial View Controller
func initialViewController(){
self.window = UIWindow(frame: UIScreen.main.bounds)
let rootViewController = UIViewController(nibName: "HomeVC", bundle: nil)
let navigation : UINavigationController = UINavigationController(rootViewController: rootViewController)
navigation.isNavigationBarHidden = true
self.window?.rootViewController = navigation
self.window?.makeKeyAndVisible()
}
in appdelegate.swift
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {
initialViewController()
return true
}
回答7:
Xcode 11 with SceneDelegate
In SceneDelegate.m
- (void)scene:(UIScene *)scene willConnectToSession:(UISceneSession *)session options:(UISceneConnectionOptions *)connectionOptions {
// Use this method to optionally configure and attach the UIWindow `window` to the provided UIWindowScene `scene`.
// If using a storyboard, the `window` property will automatically be initialized and attached to the scene.
// This delegate does not imply the connecting scene or session are new (see `application:configurationForConnectingSceneSession` instead).
self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
self.window.windowScene = (UIWindowScene *)scene;
self.viewController = [[ViewController alloc] init];
UINavigationController *navController = [[UINavigationController alloc] initWithRootViewController:self.viewController];
self.window.rootViewController = navController;
[self.window makeKeyAndVisible];
}
No need to do anything in AppDelegate.m
回答8:
This is a kind of "out of the box" solution, so it is irrelevant to your code. Specially since I don't see anything wrong with your code.
I had the same problem and tried for a long time to fix the code, what worked for me was finding an example project (in github for example) that uses xibs.
Download it and then edit it to make your application it is guaranteed to work. It is a shame that Xcode wants to force us to use their storyboards with these kinds of problems.
来源：https://stackoverflow.com/questions/31804006/starting-ios-project-without-storyboard