webclient and expect100continue

expect100continue httpwebrequest
expect: 100-continue curl

What is the best way to set expect100continue when using WebClient(C#.NET). I have this code below, I still see 100 continue in the header. Stupid apache still complains with 505 error.

        string url = "http://aaaa.com";
        ServicePointManager.Expect100Continue = false;

        WebClient service = new WebClient();           
        service.Credentials = new NetworkCredential("username", "password");

        service.UploadStringCompleted += (sender, e) => CompleteCallback(BuildResponse(e));
        service.UploadStringAsync(new Uri(url), "POST", query);

Note: If I put the above in a console app and let it run - then I do not see the headers in fiddler. But, my code is embedded in a user library which is loaded by a WPF app. So, Is there more to Expect100Continue in terms of thread, initialization, etc. Now, I think it is more of my code issue.

You need to set the Expect100Continue property on the ServicePoint used for the URI you're accessing:

var uri = new Uri("http://foo.bar.baz");
var servicePoint = ServicePointManager.FindServicePoint(uri);
servicePoint.Expect100Continue = false;

ServicePointManager.Expect100Continue Property (System.Net , When this property is set to true , 100-Continue behavior is used. Client requests that use the PUT and POST methods will add an Expect header to the request if  When Expect: 100-Continue is NOT present, HTTP follows approximately the following flow (from the client's point of view): The request initiates a TCP connection to the server. When the connection to the server is established, the full request--which includes both the request headers and the request body--is transmitted to the server.

The only way to do this is to create an override.

   public class ExpectContinueAware : System.Net.WebClient
        protected override System.Net.WebRequest GetWebRequest(Uri address)
            System.Net.WebRequest request = base.GetWebRequest(address);
            if (request is System.Net.HttpWebRequest)
                var hwr = request as System.Net.HttpWebRequest;
                hwr.ServicePoint.Expect100Continue = false;
            return request;

This works perfect.

HTTPS POST returning 100 Continue makes the WebClient throw , HTTPS POST returning 100 Continue makes the WebClient throw I use a WebClient to post some data to a server. (. Expect: 100-continue Because of the presence of older implementations, the protocol allows ambiguous situations in which a client may send "Expect: 100- continue" without receiving either a 417 (Expectation Failed) status or a 100 (Continue) status.

Try to create the WebClient instanse after you change Expect100Continue to false. Or use a Webrequest instead of a WebClient

How to disable the “Expect: 100 continue” header? · Issue #280 , Expect100Continue = false; Expect100Continue to false. bogus "405 Method Not Allowed" when it encountered the expect: 100-Continue. For example, assume the Expect100Continue property is false. When the request is sent to the server, it includes the data. When the request is sent to the server, it includes the data. If, after reading the request headers, the server requires authentication and must send a 401 response, the client must resend the data with proper

One of my below approach also worked,

In my constructor of class (service calling), you can set System.Net.ServicePointManager.Expect100Continue = false;

and then I have created BasicHttpBinding object and continued, it executed successfully.

webclient and expect100continue, What is the best way to set expect100continue when using WebClient(C#.NET). I have this code below, I still see 100 continue in the header. Stupid apache still  Hi, we have an issue whereby an 'Expect: 100-Continue' header is being automatically added to all HttpClient POST/PUT requests when our .NET Core web api service is deployed to a linux environment (specifically Ubuntu 14.04/16.04).

HttpWebRequest and the Expect: 100-continue Header Problem , Setting this to false will stop the header “Expect: 100-Continue” from for HttpWebRequest/Response, WebRequest/Response, WebClient and  System.Net.ServicePointManager.Expect100Continue = false; However, I'm writing a library and I cannot disable this for the entire appdomain, in case the application relies on this behaviour. Nor can I assume that it will remain set to this value.

TLS SSL WebClient | C# Online Compiler, using (WebClient wc = new WebClient()). 17. {. 18. 19. ServicePointManager.​Expect100Continue = true;. 20. ServicePointManager.SecurityProtocol  Post data using WebClient in C# and server replay Bad Gateway Posted on Oct 24, 2016 at 10:19 AM | 2.8k Views Follow

Act! - _very_ strange thing with PATCH request, When using a C# WebClient , with this code: try { wc = new WebClient(); wc.​Encoding Expect100Continue = false; Uri uri = new Uri(customer. Quelle est la meilleure façon de définir expect100continue avec WebClient (C # .NET). J’ai ce code ci-dessous, je vois toujours 100 continuer dans l’en-tête. Apache stupide se plaint toujours avec l’erreur 505.

  • This should be the accepted answer. Only this approach allows setting the Expect100Continue per request basis