How to use standard Sharepoint 2010 download functions

Question

I wish to download a file from a sharepoint2010 site as if you were downloading a normal document from a Document Library. What functions are available in C# to call these functions?

I know you can do so by using the following link:

http://spsite/_layouts/download.aspx?SourceUrl=UrlLocation

But i do not have a url. The file data is loaded in a Stream and i can't use anything else. If there's a way to let sharepoint download streams or if there's a work around for the missing url please let me know.

Answer 1

somthing like this:

byte[] bytes = memoryStream.GetBuffer();
Response.Buffer = true;
Response.Clear();
Response.ContentType = "application/pdf";
Response.AddHeader("content-disposition", "attachment; filename=report.pdf");
Response.BinaryWrite(bytes);
Response.Flush();

http://stackoverflow.com/questions/2239623/download-file-from-webservice-in-asp-net-site

also check this out:

// Override the ProcessRequest method. 
public void ProcessRequest(HttpContext context) 
{ 
try 
{ 
//Create and populate a memorystream with the contents of the 
//database table 
System.IO.MemoryStream mstream = GetData(); 
//Convert the memorystream to an array of bytes. 
byte[] byteArray = mstream.ToArray(); 
//Clean up the memory stream 
mstream.Flush(); 
mstream.Close(); 
// Clear all content output from the buffer stream 
context.Response.Clear(); 
// Add a HTTP header to the output stream that specifies the default filename 
// for the browser's download dialog 
context.Response.AddHeader("Content-Disposition", "attachment; filename="+context.Request.Form["txtFileName"].ToString()); 
// Add a HTTP header to the output stream that contains the 
// content length(File Size). This lets the browser know how much data is being transfered 
context.Response.AddHeader("Content-Length", byteArray.Length.ToString()); 
// Set the HTTP MIME type of the output stream 
context.Response.ContentType = "application/octet-stream"; 
// Write the data out to the client. 
context.Response.BinaryWrite(byteArray); 
} 
catch (Exception Ex) 
{ 
throw Ex; 
} 
} 
// Override the IsReusable property. 
public bool IsReusable 
{ 
get { return false; } 
} 
} 
} 

http://www.c-sharpcorner.com/UploadFile/jhblankenship/DownloadingFromMemStream11262005060834AM/DownloadingFromMemStream.aspx

and

http://forums.asp.net/t/1274439.aspx/1

hope it helps :)

Answer 2

I'm not sure if this will work in your situation but one of the things we've done in the past for a similar situation (hosted media files) is to create a SharePoint list that displays the standard file information like name, size, revision, etc, but all of that data is pulled from the external source on a schedule and the list is kept synchronized. There is a hyperlink field that links to download link on the external service so, to the end user, this appears as a file in SharePoint but the file is actually hosted remotely.

This can be kept in sync either via Timer job, a custom coded scheduled task, or, even via the Business Data Catalog if that will work for your situation.