Download ftp files over http using C#?

Question

I have a ftp server, where I have all the files stored. And it works fine with any ftp client. Now I have to download these file over HTTPS, I tried following approach but it is downloading the file in background and once download completes it asks for which location to save. It works fine if we have a small file, but when we have a large file, the browser keeps on loading till it download the file.

public ActionResult Download(string filePath)
{
    string fileName = "file.csv.gz";
    byte[] fileBytes = GetFile(@"\\myserver-ftp\f$\content\file.csv.gz");

    return File(
    fileBytes, "application/gzip", fileName);
}

 byte[] GetFile(string s)
{
    System.IO.FileStream fs = System.IO.File.OpenRead(s);
    byte[] data = new byte[fs.Length];
    int br = fs.Read(data, 0, data.Length);
    if (br != fs.Length)
        throw new System.IO.IOException(s);
    return data;
}

Answer 1

Download FluentFtp nuget package into your project.

Create a method like this:

public async Task<FtpStatus> DownloadFtpFile(string ftpPathOfFile)
{
    using (var client = new FtpClient(FtpHost))
    {
        client.Connect();
        return client.DownloadFile(localPathToDownload, ftpPathOfFile);
    }
}

Then you can call it asynchronously:

public ActionResult Download(string filePath)
    {
        string fileName = "file.csv.gz";
        var fileFullPath = @"\\myserver-ftp\f$\content\file.csv.gz";

        var ftpStatus = await DownloadFtpFile(fileFullPath);
    
        if(ftpStatus== FtpStatus.Success)
        {
           return File(GetFile(fileFullPath), "application/gzip", fileName);
        }
        else 
        {
           // return error message;
        }
    }