如何在應用程序開始時加載視圖控制器？

Question

我有一個選項卡視圖控制器作爲我的根控制器在一個應用程序中，它由3個選項卡組成，我們稱它們爲視圖A，視圖B，視圖C. 我想在應用程序啓動後立即加載這些選項卡，我認爲它可以在didFinishLaunchingWithOptions函數內完成，但我不完全確定，有誰知道該怎麼做？

感謝

Answer 1

對於這類目的的我用這個方法：

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions 
{ 
    UIWindow *window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
    self.window = window; 

    UITabBarController *tabBarController = [[UITabBarController alloc] init]; 

    rootView = [[SGMenuViewController alloc] init]; 

    UIViewController *tab1VC = [[UIViewController alloc] init]; 
    UIViewController *tab2VC = [[UIViewController alloc] init]; 
    UIViewController *tab3VC = [[UIViewController alloc] init]; 
    UIViewController *tab4VC = [[UIViewController alloc] init]; 

    navController = [[UINavigationController alloc] initWithRootViewController:rootView]; 
    UINavigationController *secondNavController = [[UINavigationController alloc] initWithRootViewController:tab3VC]; 

    NSArray* controllers = [NSArray arrayWithObjects:navController, tab2VC, secondNavController, tab4VC, nil]; 
    tabBarController.viewControllers = controllers; 

    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]; 
    self.window.rootViewController = tabBarController; 
    [self.window makeKeyAndVisible]; 
    return YES; 
} 

基本上，你創建一個UITabBarController，你把你所有的觀點存在。如果您需要在選定選項卡中推送/彈出視圖，則可以創建UINavigationController。在上面的例子中，只有1st和3rd標籤有UINavigationController，所以我可以使用self.navigationController pushViewController:。