#import "AppDelegate.h"#import "RootViewController.h"@implementation AppDelegate- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions{    self.window = [[UIWindow alloc] initWithFrame:[[UIScreen mainScreen] bounds]];    // Override point for customization after application launch.        RootViewController *rootVC=[[RootViewController alloc]init];    UINavigationController *nav=[[UINavigationController alloc]initWithRootViewController:rootVC];    self.window.rootViewController=nav;            //强制屏幕方向变为竖屏。一般是在软件开始启动的时候，会有一个欢迎页，保证欢迎页的竖屏正常运行。若启动时为横屏，则会自动变为竖屏。    [[UIApplication sharedApplication]setStatusBarOrientation:UIInterfaceOrientationPortrait animated:YES];            self.window.backgroundColor = [UIColor whiteColor];    [self.window makeKeyAndVisible];    return YES;}#pragma -mark -屏幕旋转//所有的都不支持屏幕旋转,此代码只放在AppDelegate中才有用。-(NSUInteger)application:(UIApplication *)application supportedInterfaceOrientationsForWindow:(UIWindow *)window{    return UIInterfaceOrientationMaskPortrait;}//设置屏幕是否支持旋转，YES，支持，NO不支持。不过，此代码中AppDelegate中不起作用。但是必须要写，否则会有bug-(BOOL)shouldAutorotateToInterfaceOrientation:(UIInterfaceOrientation)interfaceOrientation{    return YES;}