How to use verb GET with WebClient request?

Question

How might I change the verb of a WebClient request? It seems to only allow/default to POST, even in the case of DownloadString.

        try
        {
            WebClient client = new WebClient();               
            client.QueryString.Add("apiKey", TRANSCODE_KEY);
            client.QueryString.Add("taskId", taskId);
            string response = client.DownloadString(TRANSCODE_URI + "task");                
            result = JsonConvert.DeserializeObject<Dictionary<string, dynamic>>(response);
        }
        catch (Exception ex )
        {
            result = null;
            error = ex.Message + " " + ex.InnerException;
        }

And Fiddler says:

POST http://someservice?apikey=20130701-234126753-X7384&taskId=20130701-234126753-258877330210884 HTTP/1.1
Content-Length: 0

You are doing something very special somewhere - [DownloadString](http://msdn.microsoft.com/en-us/library/fhd1f0sw.aspx) uses GET: "...For an HTTP resource, the GET method is used". — Alexei Levenkov, Jul 02 '13 at 00:42
Strange, I figured "Download" methods would use GET. That is the entirety of my code for this request. — FlavorScape, Jul 02 '13 at 00:46
http://msdn.microsoft.com/en-us/library/system.net.webclient.aspx Yes. I figured Upload methods would use POST or PUT and Download would use GET. Strange. Nowhere else do i override WebClient or extend it. — FlavorScape, Jul 02 '13 at 17:25

score 43 · Accepted Answer · answered Jul 02 '13 at 09:32

43

If you use HttpWebRequest instead you would get more control of the call. You can change the REST verb by the Method property (default is GET)

HttpWebRequest request = (HttpWebRequest)HttpWebRequest.Create(HostURI);
request.Method = "GET";
String test = String.Empty;
using (HttpWebResponse response = (HttpWebResponse)request.GetResponse())
{
    Stream dataStream = response.GetResponseStream();
    StreamReader reader = new StreamReader(dataStream);
    test = reader.ReadToEnd();
    reader.Close();
    dataStream.Close();
 }
 DeserializeObject(test ...)

answered Jul 02 '13 at 09:32

Niklas Bjorkman

678
5
8

3

This would work. I'm just curious why WebClient in this case uses POST even for Download – FlavorScape Jul 02 '13 at 17:15
do you really have to close reader and datastream inside the using? – KeithL Mar 27 '20 at 14:39

score 3 · Answer 2 · answered Jul 02 '13 at 00:41

3

Not sure if you can use WebClient for that. But why not use HttpClient.GetAsync Method (String) http://msdn.microsoft.com/en-us/library/hh158944.aspx

answered Jul 02 '13 at 00:41

jeffo

410
1
3
9

6

hm. I want to block the caller and not use Asynchronous request. Another odd thing is HttpClient is not under namespace System.Net.Http in my 4.5 project, in fact System.Net.Http does not exist. – FlavorScape Jul 02 '13 at 00:49

score 1 · Answer 3 · answered Aug 24 '17 at 19:44

As one can see in the source code of .NET, the HTTP Method of the DownloadString depends on the state of the private WebClient instance field m_Method, which is cleared to null upon each new request method call (link) and defaults to the Web request Creator (depends on the URI, for example ftp protocol gets another creator), but this is not thread safe.

Perhaps you are sharing this WebClient instance among several calls simultaneously?

So it gets confused. Either this or the URI confuses the WebRequest creator.

How to use verb GET with WebClient request?

3 Answers3

Linked