设置 modalPresentationStyle

let mainViewController = UIView()  // 即需要被present的view
mainViewController.modalPresentationStyle = .fullScreen
self.present(mainViewController, animated: true, completion: nil)

UIViewController *vc1 = [[UIViewController alloc] init];    // vc1即需要被present的viewcontroller
vc1.modalPresentationStyle = 0;
[self presentViewController:vc animated:YES completion:nil];

presentViewController 半透明变黑

MSTestViewController *vc = [[MSTestViewController alloc] init];

vc.view.backgroundColor = [UIColor colorWithWhite:0 alpha:0.5];

float version = [UIDevice currentDevice].systemVersion.floatValue;

if (version < 8.0) { // iOS 7 实现的方式略有不同(设置self)

self.modalPresentationStyle = UIModalPresentationCurrentContext;

// iOS8以下必须使用rootViewController,否则背景会变黑

[self.view.window.rootViewController presentViewController:vc animated:YES completion:^{

}];

} else { // iOS 8 以上实现（设置vc）

vc.modalPresentationStyle = UIModalPresentationOverCurrentContext|UIModalPresentationFullScreen;

//如果控制器属于navigationcontroller或者tababrControlelr子控制器,不使用UIModalPresentationFullScreen 的话, bar 会盖住你的modal出来的控制器

[self presentViewController:vc animated:YES completion:^{

// 也可以在这里做一些完成modal后需要做得事情

}];
}

https://www.jianshu.com/p/4f96d078f1f3
https://www.jianshu.com/p/4cd8df54ed0d