How to know the length of Response (HttpWebRequest.GetResponse().GetResponseStream())

Question

Any way I can know the length of the response stream so I can show the user a percentage progress of download instead of an indeterminate one?

I find that the Response looks like below, non seekable and with no length

Answer 1

Try using the WebResponse.ContentLength property. If returns -1, it means that the remote server is not sending you the length of the response body, and therefore you cannot determine the length of the response without reading it in its entirety.

Answer 2

If you are interested, I have a code reference library that includes a WebHelper class. It's similar to the WebClient class (including the ability to report progress), but is more flexible. It is stored on CodePlex, the project name is BizArk.

It uses the Response.ContentLength property to determine the length of the response.

The ContentLength property is simply sent as part of the header from the server. There are situations where the server may not know the length of the response prior to sending the header. For example, if you are downloading a dynamically generated webpage with the buffering turned off on the server.