使所有页面都屏幕不能旋转（始终竖屏）

#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;
}