Swift 4-使用URLSession获取上传图像进度

Question

下面有这样的代码

func upload(){
    let img = UIImage(named: "1")
    let imgData = UIImageJPEGRepresentation(img!, 1)
    let data = imgData?.base64EncodedString()

    var request = URLRequest(url: URL(string: url)!)
    request.httpMethod = "POST"
    request.setValue("\(auth)", forHTTPHeaderField: "Authorization")
    request.setValue("application/xml", forHTTPHeaderField: "Content-Type")

    var postString = "<uploadrequest>"
    postString += "<folderid>123</folderid>"
    postString += "<folder_name>images</folder_name>"
    postString += "<image_byte>\(data!)</image_byte>"
    postString += "</uploadrequest>"

    request.httpBody = postString.data(using: .utf8)

    let configuration = URLSessionConfiguration.default
    let session = URLSession(configuration: configuration, delegate: self, delegateQueue: OperationQueue.main)

    let task = session.uploadTask(with: request, from: imgData!, completionHandler: {
        (data, response, error) -> Void in

        if let error = error {
            print(error)
            return
        }
        if let data = data {
            _ = self.parseJsonData(data: data)
        }
    })

    task.resume()
}

func urlSession(_ session: URLSession, task: URLSessionTask, didSendBodyData bytesSent: Int64, totalBytesSent: Int64, totalBytesExpectedToSend: Int64) {
    print("sent:", totalBytesSent, "from:", totalBytesExpectedToSend)

    let size = totalBytesSent / totalBytesExpectedToSend
    self.progressbar.progress = Float(size)
}

我的目标是使用API上传一个图像，并获得它的上传进度。该映像被转换为base64，并在API的后置字符串上插入到<image_byte>\(data!)</image_byte>。

我得到的是这样的东西：

发送: 32768从: 927220发送: 65536从: 927220发送: 131072从: 927220发送: 163840从: 927220发送: 262144从: 927220发送: 294912来自: 927220发送: 360448发送: 927220发送: 393216来自: 927220发送: 425984发送: 927220发送: 491520来自: 927220发送: 524288来自: 927220发送: 557056来自: 927220发送: 589824发送: 927220发送: 622592出发地: 927220发送: 655360从: 927220发送: 688128从: 927220发送: 720896从: 927220发送: 786432从: 927220发送: 819200从: 927220发送: 851968发送: 927220发送: 927220从: 927220发出:927220来自:927220错误Domain=NSCocoaErrorDomain Code=3840。UserInfo={NSDebugDescription=JSON文本没有以数组或对象和选项开头，以允许不设置片段。}

但是，如果我使用的是其他方法(没有uploadTask)，它可以很好地工作，但没有上传进度。

let task = URLSession.shared.dataTask(with: request, completionHandler: {
        (data, response, error) -> Void in

        if let error = error {
            print(error)
            return
        }
        if let data = data {
            _ = self.parseJsonData(data: data)
        }
    })

我也试过Alamofire了。带有request函数的Alamofire虽然成功，但仍然没有上传过程，Alamofire和upload函数(multipartformData)也犯了这个错误：

Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(error: responseSerializationFailed(原因:responseSerializationFailed Error Domain=NSCocoaErrorDomain Code=3840“字符3周围的无效值”。UserInfo={字符3.}周围的NSDebugDescription=Invalid值)

我想知道我的代码是否出错了。你能告诉我该怎么处理我的密码吗？或者问题是我的API，因为我的API只接受base64代码？

如果你想看我的Alamofire代码，那就是there

拜托，谁来帮我解决这个问题。

谢谢！:)

编辑1

这是我的请求函数的结果(没有上传功能)

{
    "media_preview" =     {
        "image_media" =         {
            fileid = 4928501;
            filename = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            folderpath = "product\\66861/images800\\";
            height = 533;
            src = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            width = 800;
        };
        "medium_media" =         {
            fileid = 4928503;
            filename = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            folderpath = "product\\66861/images500\\";
            height = 333;
            src = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            width = 500;
        };
        "small_media" =         {
            fileid = 4928503;
            filename = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            folderpath = "\product\\66861/images300\\";
            height = 200;
            src = "/zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            width = 300;
        };
        "source_media" =         {
            fileid = 4928499;
            filename = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            folderpath = "\\product\\66861images\\";
            height = 666;
            src = "/zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            width = 999;
        };
        "thumbnail_media" =         {
            fileid = 4928507;
            filename = "zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            folderpath = \\product\\66861/thumb\\";
            height = 150;
            src = "/zhzvoHBb1ogda9bps13R5IavYiadCm.jpg";
            width = 150;
        };
    };
    responsestatus =     {
        "access_token" = "<null>";
        code = 00;
        description = Success;
    };
}

编辑2这是parseJsonData(data: Data)的代码

func parseJsonData(data: Data) {
    do {
        let jsonResult = try JSONSerialization.jsonObject(with: data, options: JSONSerialization.ReadingOptions.mutableContainers) as? NSDictionary
        print(jsonResult!)
    } catch {
        print(error)
    }
}

Answer 1

要使用URLSession的以下委托方法获取进度，可以在didReceiveData方法中获得进展

func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveResponse response: NSURLResponse, completionHandler: (NSURLSessionResponseDisposition) -> Void) {

        //here you can get full lenth of your content
        expectedContentLength = Int(response.expectedContentLength)
        println(expectedContentLength)
        completionHandler(NSURLSessionResponseDisposition.Allow)
    }

    func URLSession(session: NSURLSession, dataTask: NSURLSessionDataTask, didReceiveData data: NSData) {


        buffer.appendData(data)

        let percentageDownloaded = Float(buffer.length) / Float(expectedContentLength)
        progress.progress =  percentageDownloaded
    }

    func URLSession(session: NSURLSession, task: NSURLSessionTask, didCompleteWithError error: NSError?) {
        //use buffer here.Download is done
        progress.progress = 1.0   // download 100% complete
    }

Answer 2

用于多个参数上传到服务器的图像。试试下面的代码Alamofire。会有用的。

Alamofire.upload(multipartFormData: { (multipartFormData : MultipartFormData) in
            let count = imageToUpload.count
            for (key, value) in parameters {
                multipartFormData.append((value as AnyObject).data(using: String.Encoding.utf8.rawValue)!, withName: key)
            }
            for i in 0..<count{
                let image:UIImage = self.loadImage(imageToUpload[i])
                if let imageData = image.jpegData(compressionQuality: 0.5) {
                    let imageName  = "image[\(i)]"
                    multipartFormData.append(imageData as Data, withName:imageName , fileName: imageToUpload[i], mimeType: "image/jpeg")
                }
            }
        }, usingThreshold: UInt64.init(), to: serviceUrl, method: .post, headers: headers)  { (result) in
            switch result {
            case .success(let upload, _ , _):
                upload.uploadProgress(closure: { (progress) in
                    print("uploding: \(progress.fractionCompleted)")
                })
                upload.responseJSON { response in
                    if response.result.isFailure {
                        if let err = response.error{
                            print(err)
                        }
                        return
                    }

                    guard let jsonData = response.result.value else {                           
                        return
                    }
                    //

                    do{
                        let json = try JSONSerialization.jsonObject(with: response.data as! Data, options: [])
                        print("josnResposne:\(json)")

                    } catch let parsingError {
                        print("Error", parsingError)
                    }

                }
            case .failure(let encodingError):
                print("failed")
                print(encodingError)                                        
            }
        }