使用UIDocument和Swift同步plist NSdata和iCloud

import UIKit

class MyDocument: UIDocument {
    var plistData: Data?

    override func contents(forType typeName: String) throws -> Any {
        return plistData ?? Data()
    }

    override func load(fromContents contents: Any, forType typeName: String) throws {
        if let data = contents as? Data {
            plistData = data
        }
    }
}

import UIKit

class ViewController: UIViewController {
    var document: MyDocument?

    override func viewDidLoad() {
        super.viewDidLoad()
        let fileURL = FileManager.default.url(forUbiquityContainerIdentifier: nil)?.appendingPathComponent("Documents/MyDocument.plist")
        document = MyDocument(fileURL: fileURL!)
        document?.open { success in
            if success {
                print("Document opened successfully")
                // 读取或修改 plistData
                if let data = self.document?.plistData {
                    // 处理数据
                }
            } else {
                print("Failed to open document")
            }
        }
    }

    func saveDocument() {
        document?.save(to: document!.fileURL, for: .forCreating) { success in
            if success {
                print("Document saved successfully")
            } else {
                print("Failed to save document")
            }
        }
    }
}

<key>NSUbiquitousContainers</key>
<dict>
    <key>iCloud.com.yourappidentifier</key>
    <dict>
        <key>NSUbiquitousContainerName</key>
        <string>YourAppName</string>
        <key>NSUbiquitousContainerIsDocumentScopePublic</key>
        <true/>
    </dict>
</dict>

override func contents(forType typeName: String) throws -> Any {
    guard let data = plistData else {
        throw NSError(domain: NSCocoaErrorDomain, code: NSFileReadUnknownError, userInfo: nil)
    }
    return data
}