/// 拷贝一个分片
        public void UploadPartCopy()
        {
            //.cssg-snippet-body-start:[upload-part-copy]
            try
            {
                string sourceAppid  = "1250000000";              //账号 appid
                string sourceBucket = "sourcebucket-1250000000"; //"源对象所在的存储桶
                string sourceRegion = "COS_REGION";              //源对象的存储桶所在的地域
                string sourceKey    = "sourceObject";            //源对象键
                //构造源对象属性
                COSXML.Model.Tag.CopySourceStruct copySource = new CopySourceStruct(sourceAppid,
                                                                                    sourceBucket, sourceRegion, sourceKey);

                string bucket                 = "examplebucket-1250000000"; //存储桶,格式:BucketName-APPID
                string key                    = "exampleobject";            //对象键
                string uploadId               = this.uploadId;              //初始化分块上传返回的uploadId
                int    partNumber             = 1;                          //分块编号,必须从1开始递增
                UploadPartCopyRequest request = new UploadPartCopyRequest(bucket, key,
                                                                          partNumber, uploadId);
                //设置拷贝源
                request.SetCopySource(copySource);
                //设置复制分块(指定块的范围,如 0 ~ 1M)
                request.SetCopyRange(0, 1024 * 1024);
                //执行请求
                UploadPartCopyResult result = cosXml.PartCopy(request);
                //请求成功
                //获取返回分块的eTag,用于后续CompleteMultiUploads
                this.eTag = result.copyObject.eTag;
                Console.WriteLine(result.GetResultInfo());
            }
            catch (COSXML.CosException.CosClientException clientEx)
            {
                //请求失败
                Console.WriteLine("CosClientException: " + clientEx);
            }
            catch (COSXML.CosException.CosServerException serverEx)
            {
                //请求失败
                Console.WriteLine("CosServerException: " + serverEx.GetInfo());
            }

            //.cssg-snippet-body-end
        }