How to properly create a root view controller? - iphone

Question

After upgrading to xCode 4.2 I am getting the following warning...
Applications are expected to have a root view controller at the end of application launch
After reading as much as I could find on line about the RootViewController I am not sure whether I have created my root view controller properly. I created it a long time ago when I was first learning to program in xCode.
One question I have is it ok to name the root view controller something other than RootViewController. Every example I see now has it named RootViewController. I also see it synthesized in the app delegate like this...
#synthesize rootViewController = _rootViewController;
I do not understand what this is doing. Why not just...
#synthesize rootViewController;
In any event I changed the name of my root view controller to RootViewController and followed the example I found at cupsofcocoa.com. But even after the changes I am still getting the "...expected to have a root controller..." warning.
If someone has the time to take a look and let me know what I am missing, I have listed the the significant portions of my initialization code below.
Thanks,
John
//RootViewController.h
#import <UIKit/UIKit.h>
#interface RootViewController : UIViewController {
}
#end
.
//RootViewController.m
#import "RootViewController.h"
#import "JetLoggerAppDelegate.h"
#implementation RootViewController
#end
.
//JetLoggerAppDelegate.h my app delegate
#import <UIKit/UIKit.h>
#class RootViewController;
#interface JetLoggerAppDelegate : NSObject <UIApplicationDelegate> {
UIWindow *window;
RootViewController *rootViewController;
}
#property (nonatomic, retain) IBOutlet UIWindow *window;
#property (nonatomic, retain) IBOutlet RootViewController *rootViewController;
#end
.
//.m app delegate
#import "JetLoggerAppDelegate.h"
#import "RootViewController.h" //I don't think I need this here
#implementation JetLoggerAppDelegate
#synthesize window;
#synthesize rootViewController = _rootViewController;
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
if ([launchOptions count] == 0) {
_rootViewController = [[RootViewController alloc] init];
self.window.rootViewController = self.rootViewController;
[window makeKeyAndVisible];
return YES;
}else{
[JLHelper showAlertWithTitle:#"" message:[NSString stringWithFormat:#"launchOptions: %#", launchOptions]];
}
return NO;
}
.
//main.m
#import <UIKit/UIKit.h>
int main(int argc, char *argv[]) {
NSAutoreleasePool * pool = [[NSAutoreleasePool alloc] init];
int retVal = UIApplicationMain(argc, argv, nil, #"JetLoggerAppDelegate");
[pool release];
return retVal;
}

Answer 1

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
if ([launchOptions count] == 0) {
_rootViewController = [[RootViewController alloc] init];
self.window.rootViewController = self.rootViewController;
**[window addSubview:_rootViewController.view];**
[window makeKeyAndVisible];
return YES;
}else{
[JLHelper showAlertWithTitle:#"" message:[NSString stringWithFormat:#"launchOptions: %#", launchOptions]];
return NO;
}
return nil;
}
Put return NO inside else statement and on the end put return nil; Hope this help.

Answer 2

Applications are expected to have a root view controller
Replace in AppDelegate
[window addSubview:[someController view]];
to
[self.window setRootViewController:someController];