Swift 4 - 使用 URLSession 获取上传图像进度

Question

我下面有这样的代码

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 上传图片并获取其上传进度。图像被转换为​​ base64 并插入到 API 的 poststring 上的<image_byte>\(data!)</image_byte>。

然后我得到的是这样的：

发送：32768 来自：927220 发送：65536 来自：927220 发件人：131072 发件人：927220 发送：163840 来自：927220 发送：262144 来自：927220 发送：294912 来自：927220 发件人：360448 发件人：927220 发件人：393216 发件人：927220 发件人：425984 发件人：927220 发送：491520 来自：927220 发送：524288 来自：927220 发件人：557056 发件人：927220 发件人：589824 发件人：927220 发件人：622592 发件人：927220 发送：655360 来自：927220 发件人：688128 发件人：927220 发件人：720896 发件人：927220 发件人：786432 发件人：927220 发送：819200 来自：927220 发件人：851968 发件人：927220 发送：927220 来自：927220 错误域 = NSCocoaErrorDomain 代码 = 3840 “JSON 文本没有以数组或对象开头，并且允许未设置片段的选项。” UserInfo={NSDebugDescription=JSON 文本不是以数组开头或 允许未设置片段的对象和选项。}

但是，如果我使用类似这样的其他方法（没有 uploadTask），它可以正常工作，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。 Alamofire 和 request 函数成功，但仍然没有上传进度，Alamofire 和 uploadfunction (multipartformData) 出现此错误：

responseSerializationFailed(reason: Alamofire.AFError.ResponseSerializationFailureReason.jsonSerializationFailed(error: Error Domain=NSCocoaErrorDomain Code=3840 "Invalid value around character 3." UserInfo={NSDebugDescription=Invalid value around character 3.}))

我想知道我的代码是否有错误。你能告诉我我应该如何处理我的代码吗？或者问题出在我的 API 上，因为我的 API 只接受 base64 代码？

如果你想查看我的Alamofire 代码，它是there

请有人帮我解决这个问题。

谢谢！ :)

编辑 1

这是我的请求函数的结果（没有上传函数）

{
    "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

对于上传到服务器的多个参数的图像。试试这个代码 Alamofire。它会工作。

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)                                        
            }
        }

Answer 2

获取进度使用以下 URLSession 的委托方法，您可以在didReceiveData 方法中获取进度

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
    }