如何在客户端设置请求主体

Question

Suppose I have the following web method using C# and .NET:

[WebInvoke(UriTemplage="/users", Method="POST")]
[OperationContract]
public User AddNewUser(User u);

It is expected that when you implement POST web method you will accept a request body as part of the incoming HTTP request message. The parameter u is expected to be deserialized from the incoming HTTP message body.

My question is: how do we set this request body on the client side ? It's got to be set somewhere. It really confuses me.

Besides if I added "ResponseFormat = WebMessageFormat.Json" to WebInvoke, how can I deserialize from the returned json string into the User object ?

Thanks.

Answer 1

Your question doesn't reveal what you have tried. If you are using .net on the client then you can use the DataContractSerializer to get the serialized data.

You can then use an HttpWebRequest with the method set to POST . Add the serialized data to the web request and use the GetResponse() method.

Alternatively you could use Fiddlr to test your web service using requests that you create. It gives you a concise view of exactly what is going up to the server.

Answer 2

To perform a POST request to your WCF Rest method:

    private string UseHttpWebApproach<T>(string serviceUrl, string resourceUrl, string method, T requestBody)
    {
            string responseMessage = null;                
            var request = WebRequest.Create(string.Concat(serviceUrl, resourceUrl)) as HttpWebRequest;
            if (request != null)
            {
                request.ContentType = "application/json";
                request.Method = method;
            }

            if(method == "POST" && requestBody != null)
            {                   
                byte[] requestBodyBytes = ToByteArrayUsingJsonContractSer(requestBody);                
                request.ContentLength = requestBodyBytes.Length;
                using (Stream postStream = request.GetRequestStream())
                    postStream.Write(requestBodyBytes, 0, requestBodyBytes.Length);
            }

            if (request != null)
            {
                var response = request.GetResponse() as HttpWebResponse;
                if(response.StatusCode == HttpStatusCode.OK)
                {
                    Stream responseStream = response.GetResponseStream();
                    if (responseStream != null)
                    {
                        var reader = new StreamReader(responseStream);

                        responseMessage = reader.ReadToEnd();
                    }
                }
                else
                {
                    responseMessage = response.StatusDescription;
                }
            }
            return responseMessage;
    }

    private static byte[] ToByteArrayUsingJsonContractSer<T> (T requestBody)
    {
        byte[] bytes = null;
        var serializer1 = new DataContractJsonSerializer(typeof(T));
        var ms1 = new MemoryStream();
        serializer1.WriteObject(ms1, requestBody);
        ms1.Position = 0;
        var reader = new StreamReader(ms1);
        bytes = ms1.ToArray();
        return bytes;
    }

Now Assuming your User object as shown below:

Public Class User
{
    Public int UserId  {get;set;}
    Public string UserName {get;set;}
    Public string Password  {get;set;}
}

The to call the above method i do:

User objUser = new objUser();
objUser.Username = "Test";
objUser.Password = "Test";
UseHttpWebApproach<User>(serviceBaseUrl, "users", "POST", objUser);