ios - 应用程序在 iPhone 上运行良好； iPad模拟器只给出黑屏

Question

这是来自应用程序委托(delegate)的我的 applicationDidLaunch 方法:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
[self.window makeKeyAndVisible];

                //This hides the status bar throughout the app.

[UIApplication sharedApplication].statusBarHidden=YES;


NSMutableArray *tabItems = [[NSMutableArray alloc] initWithCapacity:5];

GHHaikuViewController *hvc = [[GHHaikuViewController alloc] init];
hvc.tabBarItem.title = @"Home";
hvc.tabBarItem.image = [UIImage imageNamed:@"53-house.png"];
[tabItems addObject:hvc];

GHComposeViewController *cvc = [[GHComposeViewController alloc] init];
cvc.tabBarItem.title = @"Compose";
cvc.tabBarItem.image = [UIImage imageNamed:@"216-compose.png"];
[tabItems addObject:cvc];

GHWebViewController *wvc = [[GHWebViewController alloc] init];
wvc.tabBarItem.title = @"Buy";
wvc.tabBarItem.image = [UIImage imageNamed:@"80-shopping-cart.png"];
[tabItems addObject:wvc];

GHFeedback *fvc = [[GHFeedback alloc] init];
fvc.tabBarItem.title = @"Feedback";
fvc.tabBarItem.image = [UIImage imageNamed:@"18-envelope.png"];
[tabItems addObject:fvc];

GHSettingsViewController *svc = [[GHSettingsViewController alloc] init];
svc.tabBarItem.title = @"Settings";
svc.tabBarItem.image = [UIImage imageNamed:@"20-gear-2.png"];
[tabItems addObject:svc];

UITabBarController *tbc = [[UITabBarController alloc] init];
tbc.viewControllers = tabItems;
self.window.rootViewController = tbc;

return YES;
}

这里是来自第一个 View Controller 的 viewDidLoad，为清楚起见进行了简化:

-(void)viewDidLoad {
[super viewDidLoad];
self.view.backgroundColor = [UIColor whiteColor];
background.backgroundColor = [UIColor whiteColor];
[self.view addSubview:background];
NSLog(@"View loaded.");
}

在 iPhone 上一切正常。在 iPad(或至少是模拟器)上，“查看已加载”日志，但不是白屏，而是黑屏。早些时候我在玩 iPad 的 Storyboard，但我删除了它并且我想我删除了所有文件，现在一切都从代码运行。我已经清理了项目。我忽略了什么？

编辑:这是 Xcode 中目标摘要的截图。

Answer 1

如果您不使用主 Storyboard或 xib，则需要在代码中创建 UIWindow:

self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];