如何实现AutoFill凭据提供程序扩展- iOS 11、swift4

<key>CFBundleDisplayName</key>
<string>Credential Provider</string>
<key>CFBundleIdentifier</key>
<string>com.yourcompany.CredentialProvider</string>
<key>CFBundleVersion</key>
<string>1.0</string>
<key>CFBundleShortVersionString</key>
<string>1.0</string>
<key>NSExtensionPrincipalClass</key>
<string>$(PRODUCT_MODULE_NAME).CredentialProviderViewController</string>
<key>NSExtensionPointIdentifier</key>
<string>com.apple.identitylookup.message-filter</key>

import UIKit
import CloudKit

class CredentialProviderViewController: UIViewController {

    override func viewDidLoad() {
        super.viewDidLoad()
        // 配置视图
    }

    // 实现 CKContainer 和 CKRecord 的存储和检索逻辑
}

import CloudKit

func storeCredential(username: String, password: String) {
    let container = CKContainer.default()
    let privateDatabase = container.privateCloudDatabase
    
    let record = CKRecord(recordType: "Credential")
    record.setValue(username, forKey: "username")
    record.setValue(password, forKey: "password")
    
    privateDatabase.save(record) { (record, error) in
        if let error = error {
            print("Error saving credential: \(error.localizedDescription)")
        } else {
            print("Credential saved successfully")
        }
    }
}

func retrieveCredential(username: String) -> (username: String, password: String)? {
    let container = CKContainer.default()
    let privateDatabase = container.privateCloudDatabase
    
    let predicate = NSPredicate(format: "username == %@", username)
    let query = CKQuery(recordType: "Credential", predicate: predicate)
    
    privateDatabase.perform(query, inZoneWith: nil) { (records, error) in
        if let error = error {
            print("Error retrieving credential: \(error.localizedDescription)")
        } else if let record = records?.first {
            let username = record.value(forKey: "username") as? String ?? ""
            let password = record.value(forKey: "password") as? String ?? ""
            return (username, password)
        }
    }
    
    return nil
}