LGSemiModalNavController 介绍
LGSemiModalNavController 是一个 UINavigationController 的子类，使用
UIViewControllerAnimatedTransitioning 协议，在视图控件显示自身的动态量。
示例：
//This is an example. LGViewController *lgVC = [[LGViewController alloc]initWithFormat:LGViewControllerFormatGoBack]; //This is the nav controller LGSemiModalNavViewController *semiModal = [[LGSemiModalNavViewController alloc]initWithRootViewController:lgVC]; //Make sure to set a height on the view controller here. semiModal.view.frame = CGRectMake(0, 0, self.view.frame.size.width, 400); //Selected customization properties, see more in the header of the LGSemiModalNavViewController semiModal.backgroundShadeColor = [UIColor blackColor]; semiModal.animationSpeed = 0.35f; semiModal.tapDismissEnabled = YES; semiModal.backgroundShadeAlpha = 0.4; semiModal.scaleTransform = CGAffineTransformMakeScale(.94, .94); [self presentViewController:semiModal animated:YES completion:nil];
