iOS 13模态演示的控制高度

Question

I would like to display a view controller (with a date picker and a toolbar in it) with a overall height of 260 pt. I have set the preferred explicit size in the storyboard editor, however I believe that only affects the popover size. I have tried all the various combinations of segue/preferred presentation types, and they all display the date picker full screen. Indeed, the functionality works, however the pop up take up the whole screen.

This is what it looks like:

Answer 1

• create your ChildViewController
• add a Vertical Stack View, put everything you need inside (or any other container view)
• calculate that container's view's height
• change height of ViewController's View to that
• set corner radius of View

import UIKit

class ChildViewController: UIViewController {

    @IBOutlet weak var stackView: UIStackView!

    override func updateViewConstraints() {
        // distance to top introduced in iOS 13 for modal controllers
        // they're now "cards"
        let TOP_CARD_DISTANCE: CGFloat = 40.0

        // calculate height of everything inside that stackview
        var height: CGFloat = 0.0
        for v in self.stackView.subviews {
            height = height + v.frame.size.height
        }

        // change size of Viewcontroller's view to that height
        self.view.frame.size.height = height
        // reposition the view (if not it will be near the top)
        self.view.frame.origin.y = UIScreen.main.bounds.height - height - TOP_CARD_DISTANCE
        // apply corner radius only to top corners
        self.view.roundCorners(corners: [.topLeft, .topRight], radius: 10.0)
        super.updateViewConstraints()
    }
}

// https://stackoverflow.com/a/41197790/225503
extension UIView {
   func roundCorners(corners: UIRectCorner, radius: CGFloat) {
        let path = UIBezierPath(roundedRect: bounds, byRoundingCorners: corners, cornerRadii: CGSize(width: radius, height: radius))
        let mask = CAShapeLayer()
        mask.path = path.cgPath
        layer.mask = mask
    }
}

Code Sample here