ios - 如何设置 rootViewController？

Question

我正在尝试学习这本书，但所有示例都没有storyBoard，当我尝试构建应用程序时，我发现了这个错误：

*** Terminating app due to uncaught exception 'NSInternalInconsistencyException', reason: 'Application windows are expected to have a root view controller at the end of application launch'

我试图用这个来修复它：

ViewController *myView = [[ViewController alloc] init];
[self.window addSubview:myView];
self.window.rootViewController = myView;

但后来我收到另一个错误：

*** Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: '-[HypnoView _preferredInterfaceOrientationGivenCurrentOrientation:]: unrecognized selector sent to instance 0x78f68730'

有人可以向我解释为什么会发生在我身上吗？

Answer 1

转到 AppDelegate.m

    - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
    {
    self.window.rootViewController = self.viewController;
    return YES;
}

Answer 2

首先，您不能添加

UIViewController 

作为子视图

方法

addSubview:(UIView *)

需要一个 UIview 并且您正在添加一个 UIViewController。

其次添加子视图在 iOS 4 及更早版本中使用，现在您添加一个视图控制器作为 rootviewcontroller。

所以简单地添加，

self.window.rootViewController = myView

如果你想使用 addSubview，你需要这样做

[self.window addSubView:myView.view]

Answer 3

目标-c

@interface AppDelegate () 
    @property (nonatomic, strong) ViewController *viewController;
@end


- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    [self setViewController:[[ViewController alloc] init]];

    [self setWindow:[[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]]];
    [[self window] setBackgroundColor:[UIColor redColor];
    [[self window] setRootViewController:[self viewController]];
    [[self window] makeKeyAndVisible];

    return YES;
}

迅速

var window: UIWindow?
let viewController = ViewController();

func application(application: UIApplication, didFinishLaunchingWithOptions launchOptions: [NSObject: AnyObject]?) -> Bool {

    self.window = UIWindow(frame: UIScreen.mainScreen().bounds)
    self.window!.backgroundColor = UIColor.redColor()
    self.window!.rootViewController = playerController
    self.window!.makeKeyAndVisible()

    return true
}

Answer 4

它是这样做的。转到 AppDelegate.m 并转到 - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions

ViewController *myView = [[ViewController alloc] init];
self.window.rootViewController = myView;
[self.window makeKeyAndVisible];

如果要将 UIView 添加为子视图。然后执行以下操作：

UIView *view = [[UIView alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
[self.window makeKeyAndVisible];
[self.window addSubview:view];

Answer 5

试试这个代码

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

ViewController *controller = [[ViewController alloc]initWithNibName:@"View" bundle:nil];
UINavigationController *nav = [[UINavigationController alloc]initWithRootViewController:controller];
[self.window setRootViewController:nav];
[self.window makeKeyAndVisible];
return YES;
}

Answer 6

您需要设置：-

在 AppDelegate.m 文件中：_applicationDidFinishLaunchingWithOptions_

UIView *myView;
    self.window.rootViewController = myView

        myView= self.viewController;
        [self.window makeKeyAndVisible];