将 CloudKit 的结果快速追加到数组中

Posted 2023-02-24

【中文标题】将 CloudKit 的结果快速追加到数组中

【英文标题】：Append result of CloudKit into array in swift

【发布时间】：2021-01-12 13:46:18

【问题描述】：

我将联系人变量声明为空字符串数组

  var contact = [String] ()

然后我查询从CloudKit输出结果，当我访问控制器一次时，var contact成功添加了一个数组

let predicate = NSPredicate(value: true)
    let query = CKQuery(recordType: "Note", predicate: predicate)
    database.perform(query, inZoneWith: nil)  (record, error) in
        for record: CKRecord in record! 
            let name = record.value(forKeyPath: "content") as! String
            print ("There is a note \"\(name)\"")
            self.contact.append(name)
            
        
  

   self.contact.append (name)

  print ("There is a note \" \ (name) \ "")

但是第二次访问时，var联系人又变空了

  print ("check all array append \ (contact)")

Succes append firstime access the controller

Failed append secondtime access the controller

我在其他功能中使用可变接触

func sendSOS()

if canSendText() 

    
   
    //compese message with google link
    let googleLink = "https://www.google.com/maps/place/" + String(myLatitude!) + "+" + String(myLongtitude!)
    let SMStext = "EMERGENCY!!, Tolong Bantu saya di lokasi Latitude: " + String(myLatitude!) + "\n Longtitude: " + String(myLongtitude!) + "  " + googleLink
    let messsageCompose = MFMessageComposeViewController()
    messsageCompose.messageComposeDelegate = self
    messsageCompose.recipients = contact;
    messsageCompose.body = SMStext
    present(messsageCompose, animated: true, completion: nil)

else
    // create the alert
    let alert = UIAlertController(title: "No SMS available.", message: "Please find a better location and try again!", preferredStyle: UIAlertController.Style.alert)

    // add an action (button)
    alert.addAction(UIAlertAction(title: "OK", style: UIAlertAction.Style.default, handler: nil))

    // show the alert
    self.present(alert, animated: true, completion: nil)
    return

【问题讨论】：

缺少更多上下文：联系人何时初始化？它是某种实例吗？ ...

我在contactcontroller.swift中初始化了联系人，并在其他函数中使用

【参考方案1】：

很难确定发生了什么，因为您忽略了 contact 数组相对于 CKQuery 的初始化方式。

database.perform 行看起来有点可疑。我很确定它会返回一个 CKRecords 数组，所以你应该有：

database.perform(query, inZoneWith: nil)  records, error in
  //records is an optional array
  if let records = records
    for record in records
      //You might have to parse record.values to get its key/value pairs
      let name = record["content"] as? String ?? "No Name"
      print("There is a note: \(name)")
      //:::
      self.contact.append(name)
    
  

附带说明，我建议对所有查询使用CKQueryOperation (docs)。这是管理从 CloudKit 流出的数据的一种更简洁的方式。