如何:报告CloudKit操作的下载进度

let container = CKContainer.default()
let publicDatabase = container.publicCloudDatabase

let query = CKQuery(recordType: "YourRecordType", predicate: NSPredicate(value: true))
let queryOperation = CKQueryOperation(query: query)
queryOperation.resultsLimit = 100

var totalRecords = 0
var downloadedRecords = 0

queryOperation.recordFetchedBlock = { record in
    // 处理每个下载的记录
    // ...
    
    downloadedRecords += 1
    let progress = Double(downloadedRecords) / Double(totalRecords)
    print("下载进度：\(progress * 100)%")
}

queryOperation.queryCompletionBlock = { cursor, error in
    if let error = error {
        print("下载失败：\(error.localizedDescription)")
    } else {
        print("下载完成")
    }
}

queryOperation.progressBlock = { progress in
    // 更新总记录数
    totalRecords = Int(progress.totalUnitCount)
}

publicDatabase.add(queryOperation)