This stream does not support seek operations. HttpWebResponse

c# download httpwebrequest stream httpwebresponse

JFoulkes · Sep 17, 2009 · Viewed 15.3k times · Source

I'm making a program which downloads files over http.

I've got it downloading, however I want to be able to pause the downloads, close the program and resume them again at a later date.

I know the location i'm downloading them from supports this.

I'm downloading the file through HttpWebResponse and reading the response into a Stream using GetResponseStream.

When i close the app and restart it, I'm stuck as to how resume the download. I've tried doing a seek on the stream but it states its not supported.

What would be the best way to do this?

Answer

If the server supports this you have to send the Range Http header with your request using the AddRange method:

request.AddRange(1024);

This will instruct the server to start sending the file after the 1st kilobyte. Then just read the response stream as normal.

To test if a server supports resuming you can send a HEAD request and test if it sends the Accept-Ranges: bytes header.