.net core 3.1 分片上传

 public class xxxHelper
    {
        private readonly AmazonS3Client client;
        public xxxHelper()
        {
  
            string accessKey = "accessKey ";     //自己设置的accessKey
            string secretKey = "secretKey ";     //自己设置的secretkey

            AmazonS3Config config = new AmazonS3Config();
            config.ServiceURL = "ServiceURL ";
            config.SignatureVersion = "SignatureVersion ";
            client = new AmazonS3Client(accessKey, secretKey, config);
        }


        public async void UploadObject(string fileName, string cdnPath, string filePath)
        {
            // Create list to store upload part responses.
            List<UploadPartResponse> uploadResponses = new List<UploadPartResponse>();

            // Setup information required to initiate the multipart upload.
            InitiateMultipartUploadRequest initiateRequest = new InitiateMultipartUploadRequest
            {
                BucketName = cdnPath,
                Key = fileName
            };

            // Initiate the upload.
            // InitiateMultipartUploadResponse initResponse = client.InitiateMultipartUpload(initiateRequest);   .net framework 版本的方法
            var initResponse = await client.InitiateMultipartUploadAsync(initiateRequest);    //.net core 3.1都是异步方法，需要用await，否则报错，initResponse没有UploadId这个属性
            
            // Upload parts.
            long contentLength = new FileInfo(filePath).Length;
            long partSize = 5 * (long)Math.Pow(2, 20); // 5 MB

            try
            {
                long filePosition = 0;
                for (int i = 1; filePosition < contentLength; i++)
                {
                    UploadPartRequest uploadRequest = new UploadPartRequest
                    {
                        BucketName = cdnPath,
                        Key = fileName,
                        UploadId = initResponse.UploadId,
                        PartNumber = i,
                        PartSize = partSize,
                        FilePosition = filePosition,
                        FilePath = filePath
                    };

                    // Track upload progress.
                    uploadRequest.StreamTransferProgress += new EventHandler<StreamTransferProgressArgs>(UploadPartProgressEventCallback);

                    // Upload a part and add the response to our list.
                    var xwaitUpload = await client.UploadPartAsync(uploadRequest);
                    uploadResponses.Add(xwaitUpload);

                    filePosition += partSize;
                }

                // Setup to complete the upload.
                CompleteMultipartUploadRequest completeRequest = new CompleteMultipartUploadRequest
                {
                    BucketName = cdnPath,
                    Key = fileName,
                    UploadId = initResponse.UploadId.ToString()
                };
                completeRequest.AddPartETags(uploadResponses);

                // Complete the upload.
                Task<CompleteMultipartUploadResponse> completeUploadResponse = client.CompleteMultipartUploadAsync(completeRequest);
            }
            catch (Exception exception)
            {
                AbortMultipartUploadRequest abortMPURequest = new AbortMultipartUploadRequest
                {
                    BucketName = cdnPath,
                    Key = fileName,
                    UploadId = initResponse.UploadId.ToString()
                };
                await client.AbortMultipartUploadAsync(abortMPURequest);
            }
        }

        public void UploadPartProgressEventCallback(object sender, StreamTransferProgressArgs e)
        {
            //Console.WriteLine("{0}/{1}", e.TransferredBytes, e.TotalBytes);
            System.Diagnostics.Debug.WriteLine("{2} {0}/{1}", e.TransferredBytes, e.TotalBytes, e.IncrementTransferred);
        }