为什么DocumentPicker不在iOS上加载文件内容，而只在Mac上加载？

已排序选择器部件：

import SwiftUI
import UIKit

struct DocumentPickerViewController: UIViewControllerRepresentable {
    @Binding var isPresented: Bool
    @Binding var documentData: Data?

    func makeUIViewController(context: Context) -> UIDocumentPickerViewController {
        let documentPicker = UIDocumentPickerViewController(forOpeningContentTypes: [UTType.xml], asCopy: false)
        documentPicker.delegate = context.coordinator
        return documentPicker
    }

    func updateUIViewController(_ uiViewController: UIDocumentPickerViewController, context: Context) {
    }

    func makeCoordinator() -> Coordinator {
        return Coordinator(isPresented: $isPresented, documentData: $documentData)
    }

    class Coordinator: NSObject, UIDocumentPickerDelegate {
        @Binding var isPresented: Bool
        @Binding var documentData: Data?

        init(isPresented: Binding<Bool>, documentData: Binding<Data?>) {
            _isPresented = isPresented
            _documentData = documentData
        }

        func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
            guard let url = urls.first,
                let data = try? Data(contentsOf: url) else {
                return
            }
            documentData = data
            isPresented = false
        }

        func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
            isPresented = false
        }
    }
}

在ContentView.swift中：

Button(action: {
                    self.showDocumentPicker.toggle()
                }) {
                    Text("Load Type Tree")
                }.sheet(isPresented: $showDocumentPicker) {
                    DocumentPickerViewController(isPresented: self.$showDocumentPicker, documentData: self.$documentData)
                }
                .onReceive(Just(documentData)) { documentData in. // <-- not get called
                    sendLog(dictionary: [
                        "text": "document data received",
                    ])
                }