避免弹出窗口在水平紧凑的环境中适应全屏

根据文档 https://developer.apple.com/library/archive/featuredarticles/ViewControllerPGforiPhoneOS/PresentingaViewController.html,

在水平紧凑的环境中，弹出窗口适应 默认情况下，UIModalPresentationOverFullScreen 呈现样式。

见下图。在紧凑的环境中，弹出窗口从底部出现并动画到顶部，直到覆盖整个屏幕。

是否可以覆盖此行为并使弹出窗口仅覆盖屏幕的特定高度，如下所示？

以下代码演示了弹出窗口在紧凑环境中适应全屏呈现样式的默认行为。

import UIKit

class ViewController: UIViewController {
    
    override func viewDidLoad() {
        super.viewDidLoad()
        self.view.backgroundColor = .systemBackground
        
        let button = UIButton()
        button.translatesAutoresizingMaskIntoConstraints = false
        button.setImage(UIImage(systemName: "square.grid.2x2.fill"), for: .normal)
        button.addTarget(self, action: #selector(displayPopover), for: .touchUpInside)
        self.view.addSubview(button)
        
        NSLayoutConstraint.activate([
            button.topAnchor.constraint(equalTo: self.view.topAnchor, constant: 100),
            button.centerXAnchor.constraint(equalTo: self.view.centerXAnchor),
            button.widthAnchor.constraint(equalToConstant: 40),
            button.heightAnchor.constraint(equalToConstant: 40),
        ])
        
    }
    
    @IBAction func displayPopover(sender: UIButton!) {
        let popoverVC = PopoverViewController()
        popoverVC.preferredContentSize = CGSize(width: 300, height: 200)
        popoverVC.modalPresentationStyle = .popover
        popoverVC.popoverPresentationController?.sourceView = sender
        popoverVC.popoverPresentationController?.permittedArrowDirections = .up
        self.present(popoverVC, animated: true, completion: nil)
    }
    
    
}

class PopoverViewController: UIViewController {
    override func viewDidLoad() {
        self.view.backgroundColor = .systemGray
    }
}

Output:

此功能现已在 iOS 15 中提供。

观看 WWDC2021 短片video https://developer.apple.com/videos/play/wwdc2021/10063/

从以下位置下载 WWDC 示例项目here https://developer.apple.com/documentation/uikit/uiviewcontroller/customize_and_resize_sheets_in_uikit

 @IBAction func showImagePicker(_ sender: UIBarButtonItem) {
    
    let imagePicker = UIImagePickerController()
    imagePicker.delegate = self
    imagePicker.modalPresentationStyle = .popover
    if let popover = imagePicker.popoverPresentationController {
        popover.barButtonItem = sender
        
        let sheet = popover.adaptiveSheetPresentationController
        sheet.detents = [.medium(), .large()]
        sheet.largestUndimmedDetentIdentifier = .medium
        sheet.prefersScrollingExpandsWhenScrolledToEdge = false
        sheet.prefersEdgeAttachedInCompactHeight = true 
        sheet.widthFollowsPreferredContentSizeWhenEdgeAttached = true
    }
    
    present(imagePicker, animated: true, completion: nil)
}