如何使UIViewRepresentable继承UIView？

Question

我有一个第三方库组件的UIViewRepresentable FSCalendar。但是，我需要这个符合UIView类型.有办法这样做吗？如有任何帮助，我们将不胜感激:)

struct CalendarViewRepresentable: UIViewRepresentable {

    typealias UIViewType = FSCalendar
    var calendar = FSCalendar()

    @Binding var selectedDate: Date

    var calendarHeight: NSLayoutConstraint?


    func updateUIView(_ uiView: FSCalendar, context: Context) { }


    func makeUIView(context: Context) -> FSCalendar {

        calendar.delegate = context.coordinator
        calendar.dataSource = context.coordinator

        calendar.translatesAutoresizingMaskIntoConstraints = false

        calendar.setContentHuggingPriority(.required, for: .vertical)
        calendar.setContentHuggingPriority(.required, for: .horizontal)

        NSLayoutConstraint.activate([
            calendar.topAnchor.constraint(equalTo: context.coordinator.topAnchor)
        ])

        return calendar
    }

    func makeCoordinator() -> Coordinator {
        Coordinator(self)
    }

    class Coordinator: NSObject, FSCalendarDelegate, FSCalendarDataSource {

        var parent: CalendarViewRepresentable

        init(_ parent: CalendarViewRepresentable) {
    
            self.parent = parent     
    
        }


        func calendar(_ calendar: FSCalendar, didSelect date: Date, at monthPosition: FSCalendarMonthPosition) {

            parent.selectedDate = date
    
        }

        func calendar(_ calendar: FSCalendar, boundingRectWillChange bounds: CGRect, animated: Bool) {

            parent.calendarHeight?.constant = bounds.height
            parent.calendar.layoutIfNeeded()
    
        }
 
    }

}

struct HomeView: View {

    @State private var selectedDate: Date = Date()

    var body: some View {
  
        VStack {
            CalendarViewRepresentable(selectedDate: self.$selectedDate)
        }

    }
}

Answer 1

每当我们想要在UIKit上下文中使用该视图时，我们通常会将一个UIViewRepresentable视图(UIView)包装为UIViewRepresentable。SwiftUI使用一个名为View的视图元素。

在您的示例中，UIKit视图是FSCalendar，它最初是一个UIView，将其包装为UIViewRepresentable有助于我们将其作为SwiftUI视图在SwiftUI上下文中使用--因此没有理由将UIViewRepresentable转换为UIView。

Answer 2

使用UIViewRepresentable实现Coordinator是不完全正确的，请尝试如下：

import SwiftUI
import FSCalendar

struct CalendarViewRepresentable: UIViewRepresentable {
    
    @Binding var selectedDate: Date
    
    func makeCoordinator() -> Coordinator {
        Coordinator()
    }
    
    func makeUIView(context: Context) -> FSCalendar {
        return context.coordinator.calendar
    }
    
    func updateUIView(_ uiView: FSCalendar, context: Context) {
        uiView.select(selectedDate)
        context.coordinator.didSelectDate = { date in
            selectedDate = date
        }
    }
    
    class Coordinator: NSObject, FSCalendarDelegate, FSCalendarDataSource {
        
        lazy var calendar: FSCalendar = {
            let calendar = FSCalendar()
            calendar.delegate = self
            calendar.dataSource = self
            return calendar
        }()
        
        var didSelectDate: ((Date) -> ())?
        
        func calendar(_ calendar: FSCalendar, didSelect date: Date, at monthPosition: FSCalendarMonthPosition) {
            didSelectDate?(date)
        }
    }
}

struct FSCalendarTest: View {
    @State private var selectedDate = Date()
    
    var body: some View {
        NavigationStack {
            CalendarViewRepresentable(selectedDate: self.$selectedDate)
                .navigationTitle("\(selectedDate, format: .dateTime)")
                .toolbar {
                    Button("Now") {
                        selectedDate = Date()
                    }
                }
        }
    }
}

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