弹出全透明ViewController

PresentationVC.m

//Only work in iPad, because the modalPresentationStyle default value is UIModalPresentationFullScreen in iPhone


UIViewController* controller = self.view.window.rootViewController;
CustomUIViewController *presentationController = [[CustomUIViewController alloc]init];
controller.modalPresentationStyle = UIModalPresentationCurrentContext;
[controller presentViewController:presentationController animated:NO completion:^{}];