How to read HTTP header from response using .NET HttpWebRequest API?

问题

My app currently uses OAuth to communicate with the Twitter API. Back in December, Twitter upped the rate limit for OAuth to 350 requests per hour. However, I am not seeing this. I am still getting 150 from the account/rate_limit_status method.

I was told that I needed to use the X-RateLimit-Limit HTTP header to get the new rate limit. However, in my code, I do not see that header.

Here is my code...

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(newURL);
request.Method = "GET";
request.ServicePoint.Expect100Continue = false;
request.ContentType = "application/x-www-form-urlencoded";

using (WebResponse response = request.GetResponse())
{
    using (StreamReader reader = new StreamReader(response.GetResponseStream()))
    {
        responseString = reader.ReadToEnd();
    }
}

If I inspect the response, I can see that it has a property for Headers, and that there are 16 headers. However, I do not have X-RateLimit-Limit in the list.

_{(source: yfrog.com)}

Any idea what I am doing wrong?

回答1:

Look at the raw response text (e.g., with Fiddler). If the header isn't there, no amount of C# code is going to make it appear. :) From what you've shown, it seems the header isn't in the response.

Update: When I go to: http://twitter.com/account/rate_limit_status.xml there is no X-RateLimit-Limit header. But when I go to http://twitter.com/statuses/public_timeline.xml, it's there. So I think you just need to use a different method.

It still says 150, though!

回答2:

You should simple be able to use:

using (WebResponse response = request.GetResponse())
{
  string limit = response.Headers["X-RateLimit-Limit"];
  ...
}

If that doesn't work as expected, you can do a watch on response.Headers and see what's in there.

来源：https://stackoverflow.com/questions/2371835/how-to-read-http-header-from-response-using-net-httpwebrequest-api

标签

twitter

oauth

httpwebresponse