ios – Firebase runTransactionBlock无法在swift 3中运行

概述更新 Xcode 8并将 Swift 2项目转换为 Swift 3后,其他代码运行良好,但runTransactionBlock无法正常工作,发现此错误： “runTransactionBlock: usage detected while persistence is enabled. Please be aware that transactions will not be persisted @H_404_0@ @H_404_0@ 更新 Xcode 8并将 Swift 2项目转换为 Swift 3后,其他代码运行良好,但runTransactionBlock无法正常工作,发现此错误：

“runTransactionBlock: usage detected while persistence is enabled. Please be aware that transactions will not be persisted across app restarts”

可能有什么不对？

Firebase runTransaction Code

postRef.runTransactionBlock({ (currentData: FIRMutableData) -> FIRTransactionResult in            if var post = currentData.value as? [String : AnyObject],let uID = FIRAuth.auth()?.currentUser?.uID {                var stars : Dictionary<String,Bool>                stars = post["likeMap"] as? [String : Bool] ?? [:]                var likeCount = post["likeCount"] as? Int ?? 0                if let _ = stars[uID] {                    // Unstar the post and remove self from stars                    likeCount -= 1                    self._liked = false                    stars.removeValue(forKey: uID)                } else {                    // Star the post and add self to stars                    likeCount += 1                    self._liked = true                    stars[uID] = true                }                post["likeCount"] = likeCount as AnyObject?                post["likeMap"] = stars as AnyObject?                self._likeCount = likeCount                // Set value and report transaction success                currentData.value = post                return FIRTransactionResult.success(withValue: currentData)            }            return FIRTransactionResult.success(withValue: currentData)        }) { (error,committed,snapshot) in            if let error = error {                print(error.localizedDescription)            }        }

解决方法 不确定您使用的是哪个版本的Firebase SDK,但我将为您提供一个成功使用runTransactionBlock的基本示例：

数据库

码

let ref = FIRDatabase.database().reference()let refReservations = ref.child("reservations")refReservations.runTransactionBlock { (currentData: FIRMutableData) -> FIRTransactionResult in  if var data = currentData.value as? [String: Any] {    var count = data["count"] as? Int ?? 0    count += 1    data["count"] = count    currentData.value = data  }  return FIRTransactionResult.success(withValue: currentData)}

注意

我使用过Firebase SDK版本：3.0.1,您可以使用以下方法从代码中获取此信息：FIRDatabase.sdkVersion()

@H_404_0@ 总结

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