iOS启动时设置竖屏

在- (BOOL)application:(UIApplication )application didFinishLaunchingWithOptions:(NSDictionary )launchOptions 第一句加上

    if ([[UIApplication sharedApplication] respondsToSelector:@selector(setStatusBarOrientation:)]){        SEL selector = NSSelectorFromString(@"setStatusBarOrientation:");        NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIApplication instanceMethodSignatureForSelector:selector]];        UIDeviceOrientation orentation = UIDeviceOrientationPortrait;        [invocation setSelector:selector];        [invocation setTarget:[UIApplication sharedApplication]];        [invocation setArgument:&orentation atIndex:2];        [invocation invoke];    }