在AppDelegate中切换视图时出错

Question

我正在制作一个带有登录功能的iPhone应用程序。他们登录后，我把它写入数据库。当用户打开应用程序时，我希望它检查是否要去应用程序或显示UIView以供他们登录。我有一些代码，但它崩溃。那就是：

- (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]; 
} 
} 

而这里的错误：

-[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' 

• 数据库不是零

也许我不能这样做在该方法的操作。谁知道。任何帮助表示赞赏！
Coulton！

Answer 1

首先sleep(5);是一个坏主意，你应该避免在主线程中使用睡眠（最好不要在任何地方使用它）。

似乎你有一个文件（主应用程序委托）的所有代码，它也是一个tableview委托？这就是为什么你有这么混乱的代码，试图分成两组逻辑。

例如，你可以展示你的导航控制器的帮助下模态的观点：

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

，并使用

[self.navigationController dismissModalViewControllerAnimated:YES]; 

在iOS系统中关闭它，你可以通过呈现控制器模态显示视图用于当前视图控制器的模态视图。所以你之前加载了任何视图控制器。