如何在SwiftUI中展示交叉溶解视图？

Question

在UIKit中，我使用以下代码以呈现带有展示样式crossDissolve的模态视图控制器。

controller.modalTransitionStyle = .crossDissolve
controller.modalPresentationStyle = .overFullScreen
UIApplication.topViewController()?.present(controller, animated: true, completion: nil)

但我如何在SwiftUI中实现这个？

- Samiul Islam Sami

Answer 1

您可以像这样为UIViewController创建一个扩展:

struct ViewControllerHolder {
    weak var value: UIViewController?
}

struct ViewControllerKey: EnvironmentKey {
    static var defaultValue: ViewControllerHolder {
        return ViewControllerHolder(value: UIApplication.shared.windows.first?.rootViewController)

    }
}

extension EnvironmentValues {
    var viewController: UIViewController? {
        get { return self[ViewControllerKey.self].value }
        set { self[ViewControllerKey.self].value = newValue }
    }
}

extension UIViewController {
    func present<Content: View>(style: UIModalPresentationStyle = .automatic, transitionStyle: UIModalTransitionStyle = .coverVertical, @ViewBuilder builder: () -> Content) {
        let toPresent = UIHostingController(rootView: AnyView(EmptyView()))
        toPresent.modalPresentationStyle = style
        toPresent.modalTransitionStyle = transitionStyle
        toPresent.rootView = AnyView(
            builder()
                .environment(\.viewController, toPresent)
        )
        self.present(toPresent, animated: true, completion: nil)
    }
}

您可以根据自己的需要在SwiftUI代码中使用它：

struct ContentView: View {

    @Environment(\.viewController) private var viewControllerHolder: UIViewController?
    private var viewController: UIViewController? {
        self.viewControllerHolder
    }

    var body: some View {
        Button(action: {
            self.viewController?.present(style: .fullScreen, transitionStyle: .coverVertical) {
              Text("OK")
           }
        }) {
           Text("Present me!")
        }
    }
}

通过这种方式，您可以根据需要更改演示文稿和转换样式

- Mac3n

---

在 UIViewContrller 扩展中的 Present 函数中，您可以像这样更改它：toPresent.view.backgroundColor = yourColor。 - Mac3n

在你的视图控制器中设置 @Environment(\.presentationMode) var presentationMode，然后当你想要关闭它时，调用 self.presentationMode.wrappedValue.dismiss()。 - Mac3n

将您的变量更改为 @Environment(\.viewController) private var viewControllerHolder: UIViewController? 并在按钮操作中调用此代码：self.viewControllerHolder?.dismiss(animated: true, completion: nil)。 - Mac3n

这个视图中导航链接无法工作？ - Niharika

@Mac3n 有没有办法在 present<Content: View>(style) 方法中访问 SwiftUI 视图？ - Nirav Jain