Question

I am calling a server side function to return a json format string and parse in client side using javascript and ajax. I got parse error at javascript. I think it is the backslash JavaScriptSerializer adds to serialize object. here is the response I see from firebug:
{“d”:”{\”Item\”:\”Testing\”}”} , i understand the backslash is to escape the double quote but how do i get json to fix this problem?? i spend 3 days and do all the search at google. It seems i am doing the same way as others. Thanks for help.

Server side Code:

[System.Web.Services.WebMethod]
public static string testmethod(string serial)
{ 
    ItemList itemlist = new ItemList();
    itemlist.Item = "Testing";     
    return new System.Web.Script.Serialization.JavaScriptSerializer().Serialize(itemlist);
}

[System.Runtime.Serialization.DataContract]
public class ItemList
{
    [System.Runtime.Serialization.DataMember]
    public string Item { get; set; }
}

Client Side Javascript with ajax:

function PassParemeterToAspxUsingJquery(serial)
{               
    var sn = "test";//serial;
    $.ajax({
    type: "POST",
    url: "test.aspx/testmethod",
    contentType: "application/json; charset=utf-8",
    data: "{serial:'" + sn+"'}" ,
    dataType: "json",
    success: function(msg) {           
       alert(msg.d);             
    },
    error: function(jqXHR, textStatus, errorThrown){
       alert("The following error occured: "+ textStatus, errorThrown);
       alert(jqXHR.responseText);
    }
    });
}

Answer 1

The WebMethod won’t embed the value as part of the JSON text. If you want it serialized as a JSON Object rather than a JSON String, you have to return an Object rather than a String:

[System.Web.Services.WebMethod]
public static object testmethod(string serial)
{
    ItemList itemlist = new ItemList();
    itemlist.Item = "Testing";
    return itemList;
}

Though, this may require .NET 3.5 and a ScriptMethodAttribute:

[System.Web.Services.WebMethod]
[System.Web.Script.Services.ScriptMethod]
public static object testmethod(string serial)
{ ... }

Then just:

success: function(msg) {
   alert(msg.d.Item);
}

---

Alternatively, you should be able to work with it as is by parsing msg.d:

success: function(msg) {
    var data = $.parseJSON(msg.d);

    alert(data.Item);
}