屏幕横屏竖屏转换

//横屏
  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 = UIInterfaceOrientationLandscapeRight;
      [invocation setArgument:&val atIndex:2];
      [invocation invoke];
  }

  //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];
     
     
  }