你可以创建一些 bool 变量来检查这是第一个开始还是另一个。存储此 bool 的***位置是NSUserDefaults。好吧，如果这是第一次启动，那么显示你的LoginViewController，如果没有 - 执行常规代码：

You can create some bool variable for checking is this a first start or another. The best place to store this bool is NSUserDefaults. Well, if this is a first start then show your LoginViewController, if not - execute regular code:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { 
    UIViewController *startVC = nil;

    if (isFirstLaunch){
        startVC = [[[LoginViewController alloc] initWithNibName:@"LoginView" bundle:nil] autorelease];
    }
    else{
        startVC = [[[WorkspaceViewController alloc] initWithNibName:@"WorkspaceView" bundle:nil] autorelease];
    }

    navController = [[UINavigationController alloc] initWithRootViewController:startVC];

    [self.window makeKeyAndVisible];
    [self.window addSubview:navController.view];

    return YES;
}