HTTP POST到WCF服务

Question

I'm trying to invoke a WCF service through HTTP POST, but the service returns a 400 error. I don't know whether this is due to the OperationContract or the way I'm doing the POST. This is what the contract looks like on the server-side:

[OperationContract, WebInvoke(BodyStyle = WebMessageBodyStyle.Wrapped)]
Stream Download(string username, int fileid);

And here's how I'm trying to invoke the service through a test console app:

HttpWebRequest webRequest = WebRequest.Create("http://localhost:8000/File/Download") as   
HttpWebRequest;
webRequest.Method = "POST";
webRequest.ContentType = "application/x-www-form-urlencoded";
byte[] bytes = Encoding.ASCII.GetBytes("username=test&fileid=1");
Stream os = null;
webRequest.ContentLength = bytes.Length;
os = webRequest.GetRequestStream();
os.Write(bytes, 0, bytes.Length);
os.Close();
WebResponse webResponse = webRequest.GetResponse();

edit: I should make it clear that my goal is to test the service, and not to make it accept raw HTTP POSTs. If there's a better way I can test the service, please feel free to share.

Answer 1

This is pretty simple process, but not readily accessible or straight-forward (as is unfortunately the case with a many aspects of WCF) Please check out this post for clarification:

service contract:

[ServiceContract]
public interface ISampleService
{
    [OperationContract]
    [WebInvoke(UriTemplate = "invoke")]
    void DoWork(Stream input);
}

HTML source:

<form method="post" action="Service.svc/invoke">
    <label for="firstName">First Name</label>: <input type="text" name="firstName" value="" />
    <br /><br />
    <label for="lastName">Last Name</label>: <input type="text" name="lastName" value="" />
    <p><input type="submit" /></p>
</form>

Code Behind:

public void DoWork(Stream input)
{
    StreamReader sr = new StreamReader(input);
    string s = sr.ReadToEnd();
    sr.Dispose();
    NameValueCollection qs = HttpUtility.ParseQueryString(s);
    string firstName = qs["firstName"];
    string lastName = qs["lastName"];
}

Answer 2

If you are able to use other content types, you could instead use json, which will work in your example.

Change

webRequest.ContentType = "application/x-www-form-urlencoded";
byte[] bytes = Encoding.ASCII.GetBytes("username=test&fileid=1");

to

webRequest.ContentType = "application/json";
byte[] bytes = Encoding.ASCII.GetBytes("{\"username\":\"test\",\"fileid\":1");

If you must use the application/x-www-form-urlencoded content type, google wcf application/x-www-form-urlencoded for several posts and other SO questions describing workarounds.