如何根据Objective C中的设备加载特定的故事板？

如何解决如何根据Objective C中的设备加载特定的故事板？

这是一个转发，因为另一个已关闭。

我在自动布局方面遇到麻烦，所以我只想制作两个故事板，iPad和iPhone。我想要的只是检测设备的类型或大小，然后显示其受尊重的情节提要。我已经尝试了在StackOverflow上找到的几乎所有解决方案，但无法使其正常工作。

当前，我在DidFinishLaunchingWithOptions下的AppDelegate.m上检测设备的大小，然后加载情节提要并设置initialViewController。当我运行iPad模拟器时，它会运行并正确显示，并在控制台中返回正确的情节提要和视图控制器。但是，当我运行iPhone模拟器时，它会显示iPad故事板，但在控制台中会显示它返回了iPhone故事板和正确的initialviewcontroller。

此外，我是Objective-C的新手，但是掌握了它。谢谢，希望有人能帮忙。这是我的应用程序委托代码。

#import "AppDelegate.h"

@interface AppDelegate ()

@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
    
    // Override point for customization after application launch.
    UIStoryboard *storyboard = self.window.rootViewController.storyboard;
    UIViewController *rootViewController;
    
    // detect screen height
    int height = [UIScreen mainScreen].fixedCoordinateSpace.bounds.size.height;
    NSLog(@"The fixed height is %i",height);
    
    // determine if this is an iPad
    if (UIDevice.currentDevice.userInterfaceIdiom == UIUserInterfaceIdiomPad) {
        
        // it's an iPad
        if (height >= 1024) {
            
            storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
            rootViewController = [storyboard instantiateViewControllerWithIdentifier:@"loginViewController"];
            
            NSLog(@"LOADING MAIN/IPAD STORYBOARD");
        }
        
    } else {
        // it's an iPhone
        storyboard = [UIStoryboard storyboardWithName:@"iPhone" bundle:nil];
        rootViewController = [storyboard instantiateViewControllerWithIdentifier:@"iPhoneLoginViewController"];
        
        NSLog(@"LOADING IPHONE STORYBOARD");
    }
    
    NSLog(@"Root View Controller: %@",rootViewController);
    NSLog(@"Storyboard: %@",storyboard);
    
    self.window.rootViewController = rootViewController;
    [self.window makeKeyAndVisible];
    
    return YES;
}
#pragma mark - UIScenesession lifecycle


- (UISceneConfiguration *)application:(UIApplication *)application configurationForConnectingScenesession:(UIScenesession *)connectingScenesession options:(UISceneConnectionoptions *)options {
    // Called when a new scene session is being created.
    // Use this method to select a configuration to create the new scene with.
    return [[UISceneConfiguration alloc] initWithName:@"Default Configuration" sessionRole:connectingScenesession.role];
}


- (void)application:(UIApplication *)application diddiscardScenesessions:(NSSet<UIScenesession *> *)scenesessions {
    // Called when the user discards a scene session.
    // If any sessions were discarded while the application was not running,this will be called shortly after application:didFinishLaunchingWithOptions.
    // Use this method to release any resources that were specific to the discarded scenes,as they will not return.
}

@end

这是我的Info.plist：

Info.plist Property List

    <key>UILaunchStoryboardName</key>
    <string>LaunchScreen</string>
    <key>UIMainStoryboardFile</key>
    <string>Main</string>
    <key>UIMainStoryboardFile~ipad</key>
    <string>Main</string>
    <key>UIMainStoryboardFile~iphone</key>
    <string>iPhone</string>
    <key>UIrequiredDeviceCapabilities</key>

下面是iPad VS iPhone结果的屏幕截图：

iPad Simulator with its correct storyboard

iPhone Simulator showing incorrect storyboard

iPhone Storyboard

解决方法

您不必检测任何东西。 Info.plist 本身将根据是否是iPad来安排运行时加载不同的故事板。有一个简单的命名约定可以控制此行为：只需在 Info.plist 中输入另一个以~ipad结尾的键即可。

因此，如果要使用两个不同的主故事板，请使用 Info.plist 命名约定：配置两个“主故事板文件库名称”键，UIMainStoryboardFile和{{1 }} —或者，对于iOS 13及更高版本下的窗口场景，配置两个“应用程序场景清单”键UIMainStoryboardFile~ipad和UIApplicationSceneManifest，它们指定不同的UIApplicationSceneManifest~ipad值。