如何使FtpWebResponse异步

Question

我有这个方法：

public async Task CopyFileToOurFTP(FtpCredentialModel model)
{
    foreach (var fileName in model.FileNames)
    {
        try
        {
            string uri = model.Host + "/" + fileName;
            Uri serverUri = new Uri(uri);

            if (serverUri.Scheme != Uri.UriSchemeFtp)
            {
                return;
            }

            FtpWebRequest reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
            reqFTP.Credentials = new NetworkCredential(model.Username, model.Password);
            reqFTP.KeepAlive = false;
            reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;

            FtpWebResponse response = (FtpWebResponse)reqFTP.GetResponse();
            Stream responseStream = response.GetResponseStream();

            FileStream writeStream = new FileStream("D:\\Dev" + "\\" + fileName, FileMode.Create);                
    
            int Length = 2048;
            Byte[] buffer = new Byte[Length];
            int bytesRead = await responseStream.ReadAsync(buffer, 0, Length);

            while (bytesRead > 0)
            {  
                writeStream.Write(buffer, 0, bytesRead);
                bytesRead = await responseStream.ReadAsync(buffer, 0, Length);
            }

            writeStream.Close();
            response.Close();
        }
        catch (WebException wEx)
        {
            _logger.Error($"{wEx.Message} >>> {wEx.StackTrace}");
        }
        catch (Exception ex)
        {
            _logger.Error($"{ex.Message} >>> {ex.StackTrace}");
        }
    }
}

我的凭证模型类：

public class FtpCredentialModel
{
        public string Host { get; set; }
        public string FileMask { get; set; }
        public List<string> FileNames { get; set; }
        public string Username { get; set; }
        public string Password { get; set; }

        public FtpCredentialModel()
        {
            FileNames = new List<string>();
        }
}

和json

{
  "host": "ftp://ftp.com:21",
  "fileMask": ".txt",
"fileNames": [
"test.txt",
    "test_01.txt"
  ],
  "username": "guest",
  "password": "guest"
}

我想让它异步，并返回下载文件的计数。

据我所知，我需要让FtpWebResponse异步，但我不知道怎么做。有谁能帮帮我呢？

Answer 1

FtpWebRequest类实现了GetResponseAsync和GetRequestStreamAsync，您可以使用它们使请求异步

FtpWebRequest reqFTP;
reqFTP = (FtpWebRequest)FtpWebRequest.Create(new Uri(uri));
reqFTP.Credentials = new NetworkCredential(model.Username, model.Password);
reqFTP.KeepAlive = false;
reqFTP.Method = WebRequestMethods.Ftp.DownloadFile;
FtpWebResponse response = await reqFTP.GetResponseAsync();
Stream responseStream = await response.GetRequestStreamAsync();