Application windows are expected to have a root view controller at the end of application launch

2010년에 만들었던 앱 소스를 6년만에 열어보니 수많은 워닝과 오류들이 뜹니다.

그리고 너무도 낯설게 느껴지는 Obj-C 구문

일단 워닝들은 모두 무시하고 오류들만 하나 하나 수정하고 어찌어찌 하니 생각보다 간단하게 빌드까지 성공했습니다.

그리고는 시뮬레이터에서 실행.

실행과 동시에 사망

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Application windows are expected to have a root view controller at the end of application launch'

*** First throw call stack:

(

0   CoreFoundation                      0x00000001034abe65 __exceptionPreprocess + 165

1   libobjc.A.dylib                     0x0000000102f24deb objc_exception_throw + 48

2   CoreFoundation                      0x00000001034abcca +[NSException raise:format:arguments:] + 106

3   Foundation                          0x00000001005ac4de -[NSAssertionHandler handleFailureInMethod:object:file:lineNumber:description:] + 198

4   UIKit                               0x000000010097f218 -[UIApplication _runWithMainScene:transitionContext:completion:] + 3122

5   UIKit                               0x000000010097be7b -[UIApplication workspaceDidEndTransaction:] + 188

6   FrontBoardServices                  0x0000000104bd1754 -[FBSSerialQueue _performNext] + 192

7   FrontBoardServices                  0x0000000104bd1ac2 -[FBSSerialQueue _performNextFromRunLoopSource] + 45

8   CoreFoundation                      0x00000001033d7a31 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE0_PERFORM_FUNCTION__ + 17

9   CoreFoundation                      0x00000001033cd95c __CFRunLoopDoSources0 + 556

10  CoreFoundation                      0x00000001033cce13 __CFRunLoopRun + 867

11  CoreFoundation                      0x00000001033cc828 CFRunLoopRunSpecific + 488

12  UIKit                               0x000000010097b7cd -[UIApplication _run] + 402

13  UIKit                               0x0000000100980610 UIApplicationMain + 171

* 해결방법

기존 [window addSubview:...]  를 [window setRootViewController:...] 로 교체

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
	rootVC = [rootViewController alloc];
	// [window addSubview:rootVC.view];
    [window setRootViewController:rootVC];
    	return TRUE;
}