Question

我正在制作一个他们不是故事板的项目。

我对xib不太了解。

我遇到了从Xib推送ViewControllers的问题。

在故事板上，我曾经使用过：

 [self.navigationController pushViewController......];

但在这里我该怎么做：

我正在尝试使用此代码：

 HomeScreenVC *homeScreen = [[HomeScreenVC alloc]initWithNibName:@"HomeScreenVC" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc]initWithRootViewController:homeScreen];
[navController pushViewController:homeScreen animated:YES];

但崩溃和有效的代码是：

 UINavigationController *myNavigation = [[UINavigationController alloc] initWithRootViewController:self.signInVC];
[controller presentViewController:myNavigation animated:YES completion:nil];

我无法找到正确的方法。请协助。

Answer 1

首先尝试使用导航控制器设置viewcontroller

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
        self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];
//The first view controller
        self.firstController = [[ViewController alloc] initWithNibName:@"ViewController" bundle:nil];
//The navigation controller
        UINavigationController *navController =  [[UINavigationController alloc]initWithRootViewController:self.firstController];
        [self.window addSubview:navController.view];
        self.window.rootViewController = navController;
        [self.window makeKeyAndVisible];
        return YES;
}

让我们说ViewController是你的类推送到你的新viewcontroller，尝试以下：

@implementation ViewController

- (void)goToHomeScreen{
     HomeScreenVC *homeScreen = [[HomeScreenVC alloc]initWithNibName:@"HomeScreenVC" bundle:nil];
     [self.navigationController pushViewController:homeScreen animated:YES];
}

Answer 2

您的代码块1崩溃，原因是：

HomeScreenVC *homeScreen = [[HomeScreenVC alloc]initWithNibName:@"HomeScreenVC" bundle:nil];
UINavigationController *navController = [[UINavigationController alloc]initWithRootViewController:homeScreen];
[navController pushViewController:homeScreen animated:YES];

您已将homeScreen添加到导航控制器，并再次尝试推送同一个控制器。

您的根视图控制器（welcomeVC）没有导航控制器，因此它无法推送任何视图控制器（它只能呈现，因此阻止的第二个代码为您工作）。您必须从欢迎VC呈现导航控制器，其具有主屏幕作为根视图控制器。

或者

您需要在应用程序委托中将导航控制器添加为根视图控制器（在导航堆栈中具有WelcomeVC），然后通过简单地调用以下命令将其推送到welcomeVC中的homeVC：

[self.navigationController pushview....

AppDelegate：在此处将导航控制器设置为根视图控制器：

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

       WelcomeVC *mainViewController = [[WelcomeVC alloc]initWithNibName:@"WelcomeVC" bundle:nil]; 
       UINavigationController *navController =  [[UINavigationController alloc]initWithRootViewController: mainViewController];
        self.window.rootViewController = navController;
        [self.window makeKeyAndVisible];
        return YES;
}

然后推送到你希望的控制器：

 HomeScreenVC *homeScreen = [[HomeScreenVC alloc]initWithNibName:@"HomeScreenVC" bundle:nil];
 [self.navigationController pushViewController:homeScreen animated:YES];

如何从View Controller

2 个答案: