将通过 HTTP 上传到 ASP.NET 的文件进一步上传到 C# 和 SSH.NET 中的 SFTP 服务器

Question

I'm setting up a file transfer through Renci SSH.NET library using SFTP and C#. And I'm stuck on this problem.

Whenever I upload a file in my ASP .NET Core program it sends the file, but it sends it as an empty file with the same name.

public async Task<IActionResult> UploadFiles(List<IFormFile> files)
{
    string host = "----";
    string username = "----";
    string password = "----";
    string Name = "";
    var Stream = new MemoryStream();
    List<MemoryStream> stream = new List<MemoryStream>();
    var connectionInfo = new Renci.SshNet.ConnectionInfo(host, username, new PasswordAuthenticationMethod(username, password));
    var sftp = new SftpClient(connectionInfo);
    sftp.Connect();
    sftp.ChangeDirectory("DIRECTORY");

    try
    {
        //Read the FileName and convert it to Byte array.
        foreach (var formFile in files)
        {
            var memoryStream = new MemoryStream();
            await formFile.CopyToAsync(memoryStream);
            Name = formFile.FileName;
            using (var uplfileStream = memoryStream)
            {
                sftp.UploadFile(uplfileStream, Name, null);
            }
        }
    }

    catch (WebException ex)
    {
        throw new Exception((ex.Response as FtpWebResponse).StatusDescription);
    }
    sftp.Disconnect();
    return View("Inbox");
}

I expect an output where a file is uploaded to the server, but the actual output is a file being uploaded to the server with the same name as the file I tried to upload, but the size is 0kb aka its empty.

Answer 1

Your immediate problem is answered here:
Upload from ByteArray/MemoryStream using SSH.NET - File gets created with size 0KB

---

Though you do not need the intermediate MemoryStream (and it's inefficient anyway).

Use IFormFile.OpenReadStream :

using (var uplfileStream = formFile.OpenReadStream())
{
    sftp.UploadFile(uplfileStream, Name);
}