iOS 模拟器显示空白黑屏或白屏

Question

我正在运行一个项目，完全没有问题，但第二个项目不会出现在 iOS 模拟器中。它显示的内容取决于我在 AppDelegate.m 中的 didFinishLaunchingWithOptions 方法中的内容。

黑屏:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    return YES;
}

给出白屏:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    self.window.backgroundColor = [UIColor whiteColor];
    [self.window makeKeyAndVisible];
    return YES;
}

有任何修复的想法吗？

Answer 1

如果您使用 .xib:

在第一种情况下，你看到黑屏是因为你甚至没有创建窗口，在第二种情况下 - 你创建了白色窗口，但没有根 Controller 。

需要指定窗口的rootViewController:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
    // Override point for customization after application launch.
    // Your don't need specify window color if you add root controller, you will not see window because root controller will be above window.
    //self.window.backgroundColor = [UIColor whiteColor];

    self.window.rootViewController = [YourViewController new];

    [self.window makeKeyAndVisible];
    return YES;
}

如果你使用 Storyboard离开第一个例子:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    return YES;
}

并确保在 proj 文件中指定了主 Storyboard:

还要确保将 Storyboard 中的 View Controller 之一设置为初始 View Controller :