RecommandViewController *recommandVC = [[RecommandViewController alloc]init];    if([[[UIDevice currentDevice] systemVersion] floatValue] >= 8.0){        recommandVC.modalPresentationStyle=        UIModalPresentationOverCurrentContext|UIModalPresentationFullScreen;//if the controller has container like navigationcontroller or tababr controlelr,if you don`t use the UIModalPresentationFullScreen the bar will cover the viewcontroller        [FindAppDelegate().window.rootViewController presentViewController:recommandVC animated:NO completion:^{            recommandVC.view.backgroundColor=[UIColor clearColor];//you can figure any transparent here        }];    }else{        FindAppDelegate().window.rootViewController.modalPresentationStyle=        UIModalPresentationCurrentContext|UIModalPresentationFullScreen;//you must use the rootViewController if the system version under the iso 8.0 or the background will be black        [FindAppDelegate().window.rootViewController presentViewController:recommandVC animated:YES completion:^{            recommandVC.view.backgroundColor=[UIColor clearColor];        }];    }

主要代码：

vc.modalPresentationStyle = UIModalPresentationCustom;