UIViewControllerRepresentable高度太大了

Question

我试图将UIKit上下文菜单添加到SwiftUI视图中，因为SwiftUI上下文菜单非常有限。我设法做到了，但是UIViewControllerRepresentable占用的空间比它所需要的要多。我如何调整它的大小，以适应里面的内容？这是我的密码。

筛热

SwiftUI代码

struct TrackerCard: View {
    var tracker: Tracker
    var body: some View {
        HStack {
            HStack {
               ...
            }
            .padding()
            .background(Color("Wrapper"))
            .cornerRadius(15)
        }
        .padding(.horizontal)
    }
}

struct TrackerCardView: View {
    var tracker: Tracker
    var body: some View {
        ContextMenuView(card: TrackerCard(tracker: tracker))
    }
}

UIKit代码

class ContextMenuController : UIViewController, UIContextMenuInteractionDelegate {
    
    var card: TrackerCard?
    var hostingViewController: UIHostingController<TrackerCard>?
    
    func setViewController(_ controller : UIHostingController<TrackerCard>) {
        hostingViewController = controller
        self.addChild(controller)
        controller.view.translatesAutoresizingMaskIntoConstraints = false
        view.backgroundColor = .init(white: 1, alpha: 1)
        view.addSubview(controller.view)
        controller.didMove(toParent: self)
        controller.view.widthAnchor.constraint(equalTo: view.widthAnchor).isActive = true
    }
    
    func setInteraction() {
        let interaction = UIContextMenuInteraction(delegate: self)
        hostingViewController?.view.addInteraction(interaction)
    }
    
    func contextMenuInteraction(_ interaction: UIContextMenuInteraction, configurationForMenuAtLocation location: CGPoint) -> UIContextMenuConfiguration? {
        return ...
}

struct ContextMenuView: UIViewControllerRepresentable {
    typealias UIViewControllerType = ContextMenuController
    var card: TrackerCard
    var controller : UIViewControllerType? = nil
    
    func makeUIViewController(context: Context) -> ContextMenuController {
        let contextMenuController = controller ?? ContextMenuController()
        contextMenuController.card = card
        return contextMenuController
    }

    func updateUIViewController(_ contextMenuController: ContextMenuController, context: Context) {
        contextMenuController.setViewController(UIHostingController(rootView: card))
        contextMenuController.setInteraction()
    }
}

Answer 1

尝尝这个。首先，将.fixedSize添加到SwiftUI视图中：

ContextMenuView(card: TrackerCard(tracker: tracker))
    .fixedSize(horizontal: false, vertical: true)

这样，视图应该是水平不受约束的，但根据其首选的大小，它只需要垂直占用尽可能多的空间。

但是您可能会注意到，对于当前的布局，高度会被压缩(一直到0)。

要解决这个问题，我们需要像这样在preferredContentSize中设置UIViewController

override func viewDidLayoutSubviews() {
    super.viewDidLayoutSubviews()

    let targetSize = CGSize(width: view.bounds.width, height: UIView.layoutFittingCompressedSize.height)
    self.preferredContentSize = view.systemLayoutSizeFitting(targetSize)
}

有关这方面的更多细节，请参见博客文章自动调整大小的儿童视图。

但是高度可能仍然会被设置为0。在我的例子中，我必须为要按需要计算的首选高度(而不是0)添加一个约束。

controller.view.heightAnchor.constraint(lessThanOrEqualTo: view.heightAnchor).isActive = true

希望这能有所帮助。如果不是，如果您编辑了您的答案以包含一个显示问题的预览的最小工作示例，那就更好了。