Upload file uploaded via HTTP to ASP.NET further to FTP server in C#

Question

Upload form:

<form asp-action="Upload" asp-controller="Uploads" enctype="multipart/form-data">
<input type="file" name="file" maxlength="64" />
<button type="submit">Upload</button>

Controller/File upload:

public void Upload(IFormFile file){
    using (WebClient client = new WebClient())
    {
        client.Credentials = new NetworkCredential("xxxx", "xxxx");
        client.UploadFile("ftp://xxxx.xxxx.net.uk/web/wwwroot/images/", "STOR", file.FileName);
    }
}

Problem:

Getting error "Could not find file xxxx". I understand the issue is that it's trying to find the file as it is "C:\path-to-vs-files\examplePhoto.jpg" on the FTP server, which obviously doesn't exist. I've been looking at many questions/answers on here and I think I need some kind of FileStream read/write cod. But I'm not fully understanding the process at the moment.

Answer 1

Use IFormFile.CopyTo or IFormFile.OpenReadStream to access the contents of the uploaded file.

Combine that with WebClient.OpenWrite:

public void Upload(IFormFile file)
{
    string url = "ftp://ftp.example.com/remote/path/file.zip";
    using (WebClient client = new WebClient())
    {
        client.Credentials = new NetworkCredential("xxxx", "xxxx");
        using (var ftpStream = client.OpenWrite(url))
        {
            file.CopyTo(ftpStream);
        }
    }
}

---

Alternatively, use FtpWebRequest:

public void Upload(IFormFile file)
{
    string url = "ftp://ftp.example.com/remote/path/file.zip";
    FtpWebRequest request = (FtpWebRequest)WebRequest.Create(url);
    request.Credentials = new NetworkCredential("username", "password");
    request.Method = WebRequestMethods.Ftp.UploadFile;  
    
    using (Stream ftpStream = request.GetRequestStream())
    {
        file.CopyTo(ftpStream);
    }
}