Download file directly to memory

Question

I would like to load an excel file directly from an ftp site into a memory stream. Then I want to open the file in the FarPoint Spread control using the OpenExcel(Stream) method. My issue is I'm not sure if it's possible to download a file directly into memory. Anyone know if this is possible?

Answer 1

Yes, you can download a file from FTP to memory.

I think you can even pass the Stream from the FTP server to be processed by FarPoint.

WebRequest request = FtpWebRequest.Create("ftp://asd.com/file");

using (WebResponse response = request.GetResponse())
{
    Stream responseStream = response.GetResponseStream();
    OpenExcel(responseStream);
}

Using WebClient you can do nearly the same. Generally using WebClient is easier but gives you less configuration options and control (eg.: No timeout setting).

WebClient wc = new WebClient();
using (MemoryStream stream = new MemoryStream(wc.DownloadData("ftp://asd.com/file")))
{
    OpenExcel(stream);
}

Answer 2

Take a look at WebClient.DownloadData. You should be able to download the file directory to memory and not write it to a file first.

This is untested, but something like:

var spreadSheetStream
    = new MemoryStream(new WebClient().DownloadData(yourFilePath));

I'm not familiar with FarPoint though, to say whether or not the stream can be used directly with the OpenExcel method. Online examples show the method being used with a FileStream, but I'd assume any kind of Stream would be accepted.

Answer 3

Download file from URL to memory. My answer does not exactly show, how to download a file for use in Excel, but shows how to create a generic-purpose in-memory byte array.

    private static byte[] DownloadFile(string url)
    {
        byte[] result = null;

        using (WebClient webClient = new WebClient())
        {
            result = webClient.DownloadData(url);
        }

        return result;
    }