tencent cloud

using COSXML.Model.Object;
using COSXML.Auth;
using COSXML.Transfer;
using System;
using COSXML;
using System.Threading.Tasks;

namespace COSSnippet
{
    public class TransferDownloadObjectModel {

      private CosXml cosXml;

      TransferDownloadObjectModel() {
        CosXmlConfig config = new CosXmlConfig.Builder()
          .SetRegion("COS_REGION") // 设置默认的地域, COS 地域的简称请参照 https://www.tencentcloud.com/document/product/436/6224?from_cn_redirect=1
          .Build();

        string secretId = "SECRET_ID";   // 云 API 密钥 SecretId, 获取 API 密钥请参照 https://console.tencentcloud.com/cam/capi
        string secretKey = "SECRET_KEY"; // 云 API 密钥 SecretKey, 获取 API 密钥请参照 https://console.tencentcloud.com/cam/capi
        long durationSecond = 600;          //每次请求签名有效时长，单位为秒
        QCloudCredentialProvider qCloudCredentialProvider = new DefaultQCloudCredentialProvider(secretId, 
          secretKey, durationSecond);

        this.cosXml = new CosXmlServer(config, qCloudCredentialProvider);
      }

      /// 高级接口下载对象
      public async Task TransferDownloadObject()
      {
        // 初始化 TransferConfig
        TransferConfig transferConfig = new TransferConfig();
        // 手动设置高级下载接口的分块阈值为 20MB(默认为20MB), 从5.4.26版本开始支持！
        //transferConfig.DivisionForDownload = 20 * 1024 * 1024;
        // 手动设置高级下载接口的分块大小为 10MB(默认为5MB),不建议此处设置过小的分块值,可能导致频繁重试或下载速度不合预期
        //transferConfig.SliceSizeForDownload = 10 * 1024 * 1024;

        // 初始化 TransferManager
        TransferManager transferManager = new TransferManager(cosXml, transferConfig);

        String bucket = "examplebucket-1250000000"; //存储桶，格式：BucketName-APPID
        String cosPath = "exampleobject"; //对象在存储桶中的位置标识符，即称对象键
        string localDir = System.IO.Path.GetTempPath();//本地文件夹
        string localFileName = "my-local-temp-file"; //指定本地保存的文件名

        // 下载对象
        COSXMLDownloadTask downloadTask = new COSXMLDownloadTask(bucket, cosPath, 
          localDir, localFileName);

        // 手动设置高级下载接口的并发数 (默认为5), 从5.4.26版本开始支持！
        //downloadTask.SetMaxTasks(10);
        downloadTask.progressCallback = delegate (long completed, long total)
        {
            Console.WriteLine(String.Format("progress = {0:##.##}%", completed * 100.0 / total));
        };

        try {
          COSXML.Transfer.COSXMLDownloadTask.DownloadTaskResult result = await 
            transferManager.DownloadAsync(downloadTask);
          Console.WriteLine(result.GetResultInfo());
          string eTag = result.eTag;
        }
        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());
        }
      }


      static void Main(string[] args)
      {
        TransferDownloadObjectModel m = new TransferDownloadObjectModel();

        /// 高级接口下载对象
        m.TransferDownloadObject().Wait();
      }
    }
}