Can not read JSON data.

I am creating application where i send data in form of ajax request and accept in form of JSON, i want to display that JSON data in gridview, but not succeded in it. when i try to print data in JSON(data.d.length) it display 272 (i think it is counting spaces also). I need help in reading data from JSON and bind it to GridView.

In the below way i am sending data to webmethod in ajax request

$.ajax({

type: "POST",

url: "StudentData.aspx/GetData",

data: JSON.stringify(obj),

contentType: "application/json; charset=utf-8",

dataType: "json",

success: OnSuccess,

failure: function (response) {

alert(response.d);

error: function (response) {

alert(response.d);

}

});

Below code works perfectly fine and send data in JSON format.

[WebMethod]

//public static List GetData()

public static string GetData(string name)

{

string constr = @"connection string";

string sql = "query";

SqlDataAdapter da = new SqlDataAdapter(sql, constr);

DataSet ds = new DataSet();

da.Fill(ds);

return JsonConvert.SerializeObject(ds, Newtonsoft.Json.Formatting.Indented);

}

//In below code when i print data.d.length it display 272.

function OnSuccess(data) {

alert("In success");

alert(data.d.length);

}