iOS8以iOS8以下的系统present一个半透明的ViewC

起因

需求需要做一个引导页面，这个引导页的逻辑处理较多，如果单独一个View，不方便管理与后期的维护，所以需要做成ViewController来管理和维护
下面直接分享一下我的源码

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];
        }];
    }