ios - 多点连接 IOS : didFinishReceivingResourceWithName Error Handling (Crash)

Question

我一直在努力尝试在相对较短的时间内让 Multipeer Connectivity 在我们的应用程序中运行。大多数事情都进行得相当顺利，但我们现在遇到了一个非常令人费解的问题。

当遵循快乐的路径时，我们可以很好地传输所有数据，但是当尝试实现错误处理时......这是通过关闭 wifi 传输中完成的......我的代码......:

分享者:

func sendResource(data: Data?, name: String, fileName: String, peerId: MCPeerID){
        if data != nil{
            let url = createTransferFile(jsonData: data!, name: fileName)

            if url != nil{
                session.sendResource(at: url!, withName: name, toPeer: peerId, withCompletionHandler: { (error) -> Void in
                    if error != nil{
                        NSLog("Error in sending resource send resource: \(error!.localizedDescription)")
                    }
                })

            }
        }
    }

接收者:

func session(_ session: MCSession, didFinishReceivingResourceWithName resourceName: String, fromPeer peerID: MCPeerID, at localURL: URL, withError error: Error?) {
        NSLog("%@", "didFinishReceivingResourceWithName: \(resourceName)")
        if error != nil{
            NSLog("error in receiving")
        }
        if resourceName.contains("clinicDetails"){
            if error == nil{
                if let data = self.readClinicJsonFromFile(path: localURL){
                    NSLog("passing to broadcast delegate")
                    sendDelegate?.addClinicDetails(self, clinicDetailsJSON: data)

                }else{
                    NSLog("there was an error in finding the retrieved file in clinic retrieve finished")
                    _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController
                }
            }else{
                _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController
            }
        }else if resourceName.contains("patients"){
            //NSLog("clinicId in retrievePatient: \(json["clinicId"])")
            if error == nil{
                if let data = self.readPatientJsonFromFile(path: localURL){
                    NSLog("passing to retrieve patients delegate")
                    retrievePatientDelegate?.addPatients(self, patientJSON: data , clinicId: resourceName.components(separatedBy: "/")[1])
                }else{
                    NSLog("there was an error in finding the retrieved file in patient retrieve finished")
                     _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController

                }
            }else{
                _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController
            }
        }else if resourceName == "clinicList"{
            if error == nil{
                if let data = self.readClinicListJsonFromFile(path: localURL){
                    NSLog("passing to retrieve retrieveDelegate")
                    retrieveDelegate?.addClinics(self, clinicsJSON:  data["jsonData"] as! [[String:Any]], passcode: data["passcode"] as! String)
                }else{
                    NSLog("there was an error in finding the retrieved file in patient retrieve finished")
                    _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController
                }
            }else{
                _ = Util.showAlert(retrievePatientDelegate as! UIViewController, code: 3021, actions: nil, isCustom: true) as! AlertController
            }
        }
    }

我们收到的错误:

2017-03-06 16:52:54.416352 DC[2445:1444277] [GCKSession] Failed to send a DTLS packet with 78 bytes; sendmsg error: Can't assign requested address (49).
2017-03-06 16:52:54.416560 DC[2445:1444277] [GCKSession] SSLWrite failed, packet was not sent for participant [05280B9E] channelID [4] DTLS context [0x103043ea0] pCList [0x10e94f960]; osStatus = -9803: errno = Can't assign requested address (49).

这些行会根据剩余的进度打印出更多内容。

Then we also get the following stack in xcode (我还不能将图片直接添加到我的帖子中:<)

Stack Frame from the thread causing the error

Answer 1

由于 didFinishReceivingResourceWithName 函数中的 localURL 不是可选的，因此该错误似乎与 apples 框架中的错误有关。错误或取消进度的值为 nil。在查看崩溃线程中的每个调用然后找到相关的 SO Post 之后，我得出了这个结论。