视图控制器上的视图在 Xcode 11 上都是方形的，如何？

Question

I have tried to change it's size manually (by dragging) and still not working.

Answer 1

您可以将其内容大小设置为任何您想要的大小。

Answer 2

On iOS 13 a "Modal" segue will show the presenting controller that way by default.

If you want the view controller to occupy the whole screen, set "Full Screen" on the "presentation" setting of any segue entering that controller. Segue Settings

Answer 3

If your view presents programmatically (not via storyBoard), have this in mind: From XCode 11 and up, when you build for iPad you have to add "modalPresentationStyle = .fullScreen" to get full screen views, not square ones. As follows:

let vc = UIViewController()
vc.modalPresentationStyle = .fullScreen 
self.present(vc, animated: true, completion: nil)

If you want transparency on the new viewController, you can write ".overFullScreen", as follows:

let vc = UIViewController()
vc.modalPresentationStyle = .overFullScreen 
self.present(vc, animated: true, completion: nil)