ios 切换横竖屏

if ([[UIDevice currentDevice] respondsToSelector:@selector(setOrientation:)]) { SEL selector = NSSelectorFromString(@"setOrientation:"); NSInvocation *invocation = [NSInvocation invocationWithMethodSignature:[UIDevice instanceMethodSignatureForSelector:selector]]; [invocation setSelector:selector]; [invocation setTarget:[UIDevice currentDevice]]; int val = UIInterfaceOrientationPortrait; [invocation setArgument:&val atIndex:2]; [invocation invoke]; }

这个是  强制  竖屏的  代码！