Firebase iOS Swift致命错误：NSArray元素无法与Swift数组元素types匹配

我正试图从firebase数据库中获取数据的格式是在下面。

{ "chits": { "Chit-1": { "Bidders": [ { "bankAccNumber": "5555566966", "bankIFSC": "GFHJJHHJ", "bankName": "55666", "bidderEmail": "[e-mail]", "bidderId": "Bidder-1", "bidderName": "Venkat Desi", "bidderPhone": "9999999999", "checked": false, "paymentType": 66555 }, { "bankAccNumber": "5555566966", "bankIFSC": "GFHJJHHJ", "bankName": "55666", "bidderEmail": "[e-mail]", "bidderId": "Bidder-2", "bidderName": "Venkat Desi", "bidderPhone": "9999999999", "checked": false, "paymentType": 66555 } ], "chitId": "Chit-1", "chitName": "ABC1", "chitTotalValue": 240000, "endDate": "11/10/2018", "monthlyShare": 1000, "startDate": "11/10/2017", "totalMonths": 12 } } } 

根据上面的JSON，我创build了模型

Bidder.swift

  class Bidder { var bidderId: Int var bidderName: String var bidderEmail: String var bidderPhone : String var modeOfPayment: Int var bidderBankName: String var bidderBankAcno: String var bidderIfscCode: String var paymentArray : [[String:String]]? var chitrefArray : [String]? var ref: FIRDatabaseReference? init(bidderId: Int, bidderName: String,bidderEmail: String, bidderPhone: String, modeOfPayment: Int, bidderBankName: String, bidderBankAcno: String, bidderIfscCode: String,paymentArray: [[String:String]], chitrefArray: [String]) { self.bidderId = bidderId self.bidderName = bidderName self.bidderEmail = bidderEmail self.bidderPhone = bidderPhone self.modeOfPayment = modeOfPayment self.bidderBankName = bidderBankName self.bidderBankAcno = bidderBankAcno self.bidderIfscCode = bidderIfscCode self.paymentArray = paymentArray self.chitrefArray = chitrefArray self.ref = nil } init(snapshot: FIRDataSnapshot) { let snapshotValue = snapshot.value as! [String: AnyObject] bidderId = snapshotValue["bidderId"] as! Int bidderName = snapshotValue["bidderName"] as! String bidderEmail = snapshotValue["bidderEmail"] as! String bidderPhone = snapshotValue["bidderPhone"] as! String modeOfPayment = snapshotValue["modeOfPayment"] as! Int bidderBankName = snapshotValue["bidderBankName"] as! String bidderBankAcno = snapshotValue["bidderBankAcno"] as! String bidderIfscCode = snapshotValue["bidderIfscCode"] as! String paymentArray = snapshotValue["paymentArray"] as? [[String : String]] chitrefArray = snapshotValue["chitrefArray"] as? [String] ref = snapshot.ref } func toAnyObject() -> Any { return [ "bidderId" : bidderId, "bidderName" : bidderName, "bidderEmail": bidderEmail, "bidderPhone": bidderPhone, "modeOfPayment": modeOfPayment, "bidderBankName":bidderBankName, "bidderBankAcno": bidderBankAcno, "bidderIfscCode":bidderIfscCode, "paymentArray": paymentArray as Any, "chitrefArray" : chitrefArray as Any ] } } 

ChitObject.swift

 class ChitObject { var chitId : Int var chitName: String var startDate: String var endDate : String var chitTotalAmt: Int var chitTotalMonths: Int var bidders: [Bidder] var ref: FIRDatabaseReference? init(chitId: Int,chitName: String, startDate: String, endDate: String, chitTotalAmt: Int, chitTotalMonths: Int, bidders: [Bidder]) { self.chitId = chitId self.chitName = chitName self.startDate = startDate self.endDate = endDate self.chitTotalAmt = chitTotalAmt self.chitTotalMonths = chitTotalMonths self.bidders = bidders self.ref = nil } init(snapshot: FIRDataSnapshot) { let snapshotValue = snapshot.value as! [String: AnyObject] chitId = snapshotValue["chitId"] as! Int chitName = snapshotValue["chitName"] as! String startDate = snapshotValue["startDate"] as! String endDate = snapshotValue["endDate"] as! String chitTotalAmt = snapshotValue["chitTotalAmt"] as! Int chitTotalMonths = snapshotValue["chitTotalMonths"] as! Int bidders = snapshotValue["bidders"] as! [Bidder] ref = snapshot.ref } func toAnyObject() -> Dictionary<String, Any> { return [ "chitId" : chitId, "chitName": chitName, "startDate": startDate, "endDate": endDate, "chitTotalAmt":chitTotalAmt, "chitTotalMonths": chitTotalMonths, "bidders":bidders.map({$0.toAnyObject()}) ] } } 

但是，在Viewcontroller中，我试图从下面的代码中获取biddersList 。

 var chitsArray = [ChitObject]() ChitUtils.chitRef.queryOrdered(byChild: "chitId").observe(.value, with: { snapshot in if snapshot.childrenCount > 0 { self.chitsArray.removeAll() for item in snapshot.children { let chitItem = ChitObject(snapshot: item as! FIRDataSnapshot) self.chitsArray.append(chitItem) } self.chitsArray = self.chitsArray.reversed() print(self.chitsArray.first!.bidders) ChitUtils.lastChitId = (self.chitsArray.first?.chitId)! + 1 self.chitsTableView.reloadData() } }) 

致命错误只发生在试图访问print(self.chitsArray.first!.bidders) 组在print(self.chitsArray.first!.bidders) 。 但是，arrays计数似乎一直是正确的。

Answer 1

问题在于你的ChitObject类，具体在这里：

 bidders = snapshotValue["bidders"] as! [Bidder] 

您需要创build一个投标人数组，并将其分配给投标人variables。 循环访问您从snapshotValue [“bidders”]获得的数组，并为每个值创buildBidders对象，并将其分配到Swift数组中。

我还没有使用Firebase，但是这样的事情可能会起作用：

 init(snapshot: FIRDataSnapshot) { let snapshotValue = snapshot.value as! [String: AnyObject] chitId = snapshotValue["chitId"] as! Int chitName = snapshotValue["chitName"] as! String startDate = snapshotValue["startDate"] as! String endDate = snapshotValue["endDate"] as! String chitTotalAmt = snapshotValue["chitTotalAmt"] as! Int chitTotalMonths = snapshotValue["chitTotalMonths"] as! Int if let biddersArray = snapshotValue["bidders"] as? [[String:Any]] { bidders = biddersArray.flatMap{Bidder(dict:$0)} } ref = snapshot.ref } 

编辑：

 class Bidder { var bidderId: Int var bidderName: String var bidderEmail: String var bidderPhone : String var modeOfPayment: Int var bidderBankName: String var bidderBankAcno: String var bidderIfscCode: String var paymentArray : [[String:String]]? var chitrefArray : [String]? var ref: FIRDatabaseReference? convenience init?(dict:[String:Any]) { guard let bidderId = dict["bidderId"] as? Int, let bidderName = dict["bidderName"] as? String, let bidderEmail = dict["bidderEmail"] as? String, let bidderPhone = dict["bidderPhone"] as? String, let modeOfPayment = dict["paymentType"] as? Int, let bidderBankName = dict["bankName"] as? String, let bidderBankAcno = dict["bankAccNumber"] as? String, let bidderIfscCode = dict["bankIFSC"] as? String else { return nil } self.init(bidderId: bidderId, bidderName: bidderName, bidderEmail: bidderEmail, bidderPhone: bidderPhone, modeOfPayment: modeOfPayment, bidderBankName: bidderBankName, bidderBankAcno: bidderBankAcno, bidderIfscCode: bidderIfscCode, paymentArray: [[]], chitrefArray: []) } init(bidderId: Int, bidderName: String,bidderEmail: String, bidderPhone: String, modeOfPayment: Int, bidderBankName: String, bidderBankAcno: String, bidderIfscCode: String,paymentArray: [[String:String]], chitrefArray: [String]) { self.bidderId = bidderId self.bidderName = bidderName self.bidderEmail = bidderEmail self.bidderPhone = bidderPhone self.modeOfPayment = modeOfPayment self.bidderBankName = bidderBankName self.bidderBankAcno = bidderBankAcno self.bidderIfscCode = bidderIfscCode self.paymentArray = paymentArray self.chitrefArray = chitrefArray self.ref = nil } init(snapshot: FIRDataSnapshot) { let snapshotValue = snapshot.value as! [String: AnyObject] bidderId = snapshotValue["bidderId"] as! Int bidderName = snapshotValue["bidderName"] as! String bidderEmail = snapshotValue["bidderEmail"] as! String bidderPhone = snapshotValue["bidderPhone"] as! String modeOfPayment = snapshotValue["modeOfPayment"] as! Int bidderBankName = snapshotValue["bidderBankName"] as! String bidderBankAcno = snapshotValue["bidderBankAcno"] as! String bidderIfscCode = snapshotValue["bidderIfscCode"] as! String paymentArray = snapshotValue["paymentArray"] as? [[String : String]] chitrefArray = snapshotValue["chitrefArray"] as? [String] ref = snapshot.ref } func toAnyObject() -> Any { return [ "bidderId" : bidderId, "bidderName" : bidderName, "bidderEmail": bidderEmail, "bidderPhone": bidderPhone, "modeOfPayment": modeOfPayment, "bidderBankName":bidderBankName, "bidderBankAcno": bidderBankAcno, "bidderIfscCode":bidderIfscCode, "paymentArray": paymentArray as Any, "chitrefArray" : chitrefArray as Any ] } }