Return JSON from ASMX web service, without XML wrapper?

Question

I need to get Json data from a C# web service.

I know there are several questions based on this, trust me I have read through quite a few but only to confuse me further.

This is what I have done :

In my web service I have included : [System.Web.Script.Services.ScriptService] for the class & [ScriptMethod(ResponseFormat = ResponseFormat.Json, UseHttpGet = true)] for the method

I have also used a JavaScriptSerializer() to convert my data to a string

I am calling this service using $.getJSON()

If I don't use that I get an Cross domain reference error.

To do this I had to setup m service to get the callback function name so I am passing this.Context.Request["callback"] + serialized Json Data;

But in the output I get it wrapped in

< string xmlns="http://XYZ..."> 

The data within the tags is in the format I need

I also tried setting content type using : $.ajaxSetup({ scriptCharset: "utf-8" , contentType: "application/json; charset=utf-8"});

But still no success.

Addded later: I accepted frenchie's anwser beacuse I know it is the correct approach but I stil cud not get it to work... I just put the webservice & website in the same domain & used xml, I know it wasnt the best way, but I had spent 2 days on it & could not afford to waste more.

• Yuck: Are you using WCF, ASMX? You could very easily return JSON data using ASP .NET MVC as well.
• Zoidberg: Have you considering using a RESTful service? That might work better for you in this case.
• Praneeta: I am using ASMX... Very new to C# web services....I generally use PHP & its done so easily.
• John Saunders: ASMX is the old, legacy technology, and should not be used for new development. You should use WCF instead.
• Praneeta: @Zoidberg: can u please give me some pointers to restful... I believe i am using that.. <webServices> <protocols> <add name="HttpSoap"/> <add name="HttpPost"/> <add name="HttpGet"/> <add name="HttpPostLocalhost"/> <add name="Documentation"/> </protocols> </webServices>

Answer 1

Use this:

var JsonString = ....;
$.ajax({
 type: "POST",
 contentType: "application/json; charset=utf-8",
 url: "YourWebServiceName.asmx/yourmethodname",
 data: "{'TheData':'" + JsonString + "'}",
 dataType: "json",
 success: function (msg) {
 var data = msg.hasOwnProperty("d") ? msg.d : msg;
 OnSucessCallBack(data);
 },
 error: function (xhr, status, error) {
 alert(xhr.statusText);
 }
});
function OnSuccessCallData(DataFromServer) {
 // your handler for success 
}

and then on the server side, in the code behind file that's auto-generated in your AppCode folder, you write something like this:

using System.Web.Services;
using System.Web.Script.Serialization;
 [System.Web.Script.Services.ScriptService]
 public class YourWebServiceName : System.Web.Services.WebService
 {
 [WebMethod]
 public string yourmethodname(string TheData)
 {
 JavascriptSerializer YourSerializer = new JavascriptSerializer();
 // custom serializer if you need one 
 YourSerializer.RegisterConverters(new JavascriptConverter [] { new YourCustomConverter() });
 //deserialization
 TheData.Deserialize(TheData);
 //serialization 
 TheData.Serialize(TheData);
 }
 }

If you don't use a custom converter, the properties between the json string and the c# class definition of your server-side object must match for the deserialization to work. For the serialization, if you don't have a custom converter, the json string will include every property of your c# class. You can add [ScriptIgnore] just before a property definition in your c# class and that property will be ignored by the serializer if you don't specify a custom converter.

• Praneeta: Do I need to serialize the data using JavaScriptSerializer() before sending or do I just send the data as it is?
• frenchie: yes, you need to serialize it. You can either use straight serialization or use a custom serializer. Updating code.
• frenchie: Just updated the code. This is verbatim what I use and it works. Let me know if this helps.
• Praneeta: I was doing it this way: JavaScriptSerializer js = new JavaScriptSerializer(); string strJSON = js.Serialize(locs); locs is an array of objects.. Is this an acceptable way?
• frenchie: Yes, if you have an array of objects the serializer will do the job just fine. I really recommend using a custom converter because the property names you have can be shortened when you're serializing the objects for the web. You got your thing working?