如何从Ajax调用WCF服务？

Question

I have a WCF service as given below-

 [ServiceContract(Namespace = "")]
[AspNetCompatibilityRequirements(RequirementsMode = AspNetCompatibilityRequirementsMode.Allowed)]
public class Sync
{
    [OperationContract]
    [WebInvoke]
    public string SyncDataNow(UserData obj)
    {
        try
        {
            using (MavenifyEntities db = new MavenifyEntities())
            {
                bool userExist = db.Users.Any(u => u.Id == obj.UserId);
                if (userExist)
                {
                    DataSync data = new DataSync();
                    data.UserId = obj.UserId;
                    data.TempId = obj.TempId;
                    data.Content = obj.Content;
                    data.CreatedDate = DateTime.Now.ToString();
                    db.DataSyncs.Add(data);
                    db.SaveChanges();
                    return "1";
                }
                else
                {
                    return "0";
                }
            }
        }
        catch (Exception ex)
        {
            return "error";
        }
    }
}

[DataContract(Namespace = "")]
public class UserData
{
    [DataMember]
    public int UserId { get; set; }
    [DataMember]
    public string Content { get; set; }
    [DataMember]
    public string TempId { get; set; }
}

When I am calling this service from POSTMAN, it receives null data, Please help me to find out what's wrong I am doing.

I am sending raw data in json format like-

{"UserData":{"UserId":"1","TempId":"asdbsjiadf","Content":"Hello"}}.

my web.config entries are-

 <system.serviceModel>
<behaviors>
  <endpointBehaviors>
    <behavior name="PhoneSync.SyncAspNetAjaxBehavior">
      <enableWebScript />
    </behavior>
  </endpointBehaviors>
</behaviors>
<serviceHostingEnvironment aspNetCompatibilityEnabled="true" multipleSiteBindingsEnabled="true" />
<services>
  <service name="PhoneSync.Sync">
    <endpoint address="" behaviorConfiguration="PhoneSync.SyncAspNetAjaxBehavior" binding="webHttpBinding" contract="PhoneSync.Sync" /> 
  </service>
</services>

Answer 1

You should use Wcf Rest WebHttpBinding also You will face with Cross Domain Messaging issue. So You will disable cross messaging security or create own behavior for jsonp

also your message should be {"UserId":"1","TempId":"asdbsjiadf","Content":"Hello"} for your signature. if you want to use {"UserData":{"UserId":"1","TempId":"asdbsjiadf","Content":"Hello"}} you should wrap it

Answer 2

Make sure that request/response by default is Json . I would specify that explicitly in [WebInvoke(RequestFormat = WebMessageFormat.Json, ResponseFormat=WebMessageFormat.Json)]

And maybe make sense do configure some options like suggested here

Answer 3

I have resolved the problem by changing the name "UserData" to "obj" in my json ie changing

{"UserData":{"UserId":"1","TempId":"asdbsjiadf","Content":"Hello"}}

to

{"obj":{"UserId":"1","TempId":"asdbsjiadf","Content":"Hello"}}

now I am receiving the data in my services. But I am unable to get why it is happening. Please share the cause.