Question

I am making a iPhone app with a login feature. After they login, I have it write to a database. When the user opens the app, I want it to check whether or not to go to the app or show a UIView for them to login. I have some code, but it crashes. Here it is:

- (void)applicationDidFinishLaunching:(UIApplication *)application {    
sleep(5);
// Configure and show the window
[window addSubview:[navigationController view]];
[window makeKeyAndVisible];
//[application setStatusBarStyle:UIStatusBarStyleBlackOpaque];

int checkLoginCount = 0;
NSArray *checkLoginInfo = [database executeQuery:@"SELECT * FROM login WHERE id != '' or email != '' or password != ''"];   
for (NSDictionary *checkLoginRow in checkLoginInfo) {
    checkLoginCount++;
}

NSLog(@"alsdfjaldfksjalsdfjkas %d", checkLoginCount);

if (checkLoginCount == 0) {
    SplashPageViewController *screentwo = [[SplashPageViewController alloc] initWithNibName:@"splashPage" bundle:nil];
    //NSLog(@"aldjksflasdfjadksaldfjsaldksfj %@", screentwo);
    screentwo.modalTransitionStyle = UIModalTransitionStyleCoverVertical;
    [self presentModalViewController:screentwo animated:NO];
    [screentwo release];
} else {
    splashView = [[UIImageView alloc] initWithFrame:CGRectMake(0,0, 320, 480)];
    splashView.image = [UIImage imageNamed:@"Default.png"];
    [window addSubview:splashView];
    [window bringSubviewToFront:splashView];
    [UIView beginAnimations:nil context:nil];
    [UIView setAnimationDuration:0.5];
    [UIView setAnimationTransition:UIViewAnimationTransitionNone forView:window cache:YES];
    [UIView setAnimationDelegate:self]; 
    [UIView setAnimationDidStopSelector:@selector(startupAnimationDone:finished:context:)];
    splashView.alpha = 0.0;
    //splashView.frame = CGRectMake(-60, -60, 440, 600);
    [UIView commitAnimations];
}
}

And here’s the error:

-[TableViewAppDelegate presentModalViewController:animated:]: unrecognized selector sent to instance 0x4e3e860
TableView[15309:207] *** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[TableViewAppDelegate presentModalViewController:animated:]: unrecognized selector sent to instance 0x4e3e860'
*** Call stack at first throw:
(
0   CoreFoundation                      0x00fccbe9 __exceptionPreprocess + 185
1   libobjc.A.dylib                     0x011215c2 objc_exception_throw + 47
2   CoreFoundation                      0x00fce6fb -[NSObject(NSObject) doesNotRecognizeSelector:] + 187
3   CoreFoundation                      0x00f3e366 ___forwarding___ + 966
4   CoreFoundation                      0x00f3df22 _CF_forwarding_prep_0 + 50
5   TableView                           0x00002b02 -[TableViewAppDelegate applicationDidFinishLaunching:] + 473
6   UIKit                               0x002e6253 -[UIApplication _callInitializationDelegatesForURL:payload:suspended:] + 1252
7   UIKit                               0x002e855e -[UIApplication _runWithURL:payload:launchOrientation:statusBarStyle:statusBarHidden:] + 439
8   UIKit                               0x002f2db2 -[UIApplication handleEvent:withNewEvent:] + 1533
9   UIKit                               0x002eb202 -[UIApplication sendEvent:] + 71
10  UIKit                               0x002f0732 _UIApplicationHandleEvent + 7576
11  GraphicsServices                    0x0186fa36 PurpleEventCallback + 1550
12  CoreFoundation                      0x00fae064 __CFRUNLOOP_IS_CALLING_OUT_TO_A_SOURCE1_PERFORM_FUNCTION__ + 52
13  CoreFoundation                      0x00f0e6f7 __CFRunLoopDoSource1 + 215
14  CoreFoundation                      0x00f0b983 __CFRunLoopRun + 979
15  CoreFoundation                      0x00f0b240 CFRunLoopRunSpecific + 208
16  CoreFoundation                      0x00f0b161 CFRunLoopRunInMode + 97
17  UIKit                               0x002e7fa8 -[UIApplication _run] + 636
18  UIKit                               0x002f442e UIApplicationMain + 1160
19  TableView                           0x000027f6 main + 84
20  TableView                           0x00002799 start + 53
21  ???                                 0x00000001 0x0 + 1
)
terminate called after throwing an instance of 'NSException'

• database isn’t nil

Maybe I can’t do that action in that method. Who knows. Any help is appreciated!
Coulton!

Answer 1

First of all sleep(5); is a bad idea, you should avoid using sleep on the main thread (and better don’t use it anywhere).

Seems that you have all your code in one file (main app delegate) and it also is a tableview delegate? Thats why you have so messy code, try to divide logic in two groups.

For example, you can show your modal views with the help of navigation controller:

[[self navigationController] presentModalViewController:modalViewController animated:YES];

and dismiss it using

[self.navigationController dismissModalViewControllerAnimated:YES];

In iOS, you can display views modally by presenting the controller for the modal view from your current view controller. So you have get any view controller loaded before.