在SwiftUI DocumentGroup macOS中创建并打开新文档

import SwiftUI
import UniformTypeIdentifiers

struct MyDocument: FileDocument {
    static var readableContentTypes = [UTType.plainText]
    
    var text: String
    
    init(text: String = "") {
        self.text = text
    }
    
    init(configuration: ReadConfiguration) throws {
        guard let data = configuration.file.regularFileContents,
              let string = String(data: data, encoding: .utf8) else {
            throw CocoaError(.fileReadCorruptFile)
        }
        text = string
    }
    
    func fileWrapper(configuration: WriteConfiguration) throws -> FileWrapper {
        let data = text.data(using: .utf8) ?? Data()
        return FileWrapper(regularFileWithContents: data)
    }
}

struct ContentView: View {
    @Binding var document: MyDocument
    
    var body: some View {
        TextEditor(text: $document.text)
    }
}

@main
struct MyApp: App {
    @StateObject private var myDocument = MyDocument()
    
    var body: some Scene {
        DocumentGroup(newDocument: MyDocument()) { file in
            ContentView(document: file.$document)
        }
    }
}