Question

Im trying to get a page talking to a webservice through jquery.

this is the jquery:

function Test(item) {
  $.ajax({
    type: "POST",
    url: "WebService.asmx/test",
    data: '{' +
                    'Item:"' + item + '"' +
               '}',
    contentType: "application/json; charset=utf-8",
    dataType: "json",
    success: function (msg) {
        var data = jQuery.parseJSON(msg);
        if (!data.error) {
            alert("YES!!");
        }
        else {
            alert("Error" + " " + data.error);
        }
    },
    error: function (msg) {
        alert('Get Details Failure: ' + msg);
    }
 });
};

This is the web service:

    using System;
using System.Collections.Generic;
using System.Web;
using System.Web.Services;
using System.Data.SqlClient;
using System.Web.Script.Services;
using System.Web.Script.Serialization;

[WebService(Namespace = "http://tempuri.org/")]
[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]
[ScriptService]
public class WebService : System.Web.Services.WebService {

    public WebService () {}

    [WebMethod]
    [ScriptMethod(UseHttpGet = true, ResponseFormat = ResponseFormat.Json)]
    public string Test(string Item)
    {
        JavaScriptSerializer js = new JavaScriptSerializer();
        string strJSON = js.Serialize(Item);
        return strJSON;
    }
    }

but i get his error:

System.InvalidOperationException: Request format is invalid: application/json; charset=utf-8.
at System.Web.Services.Protocols.HttpServerProtocol.ReadParameters()
at System.Web.Services.Protocols.WebServiceHandler.CoreProcessRequest()

why???

Answer 1

 data: '{' +
                    'Item:"' + item + '"' +
               '}',

needs to be:

data: JSON.stringify({Item: item}),

that will produce:

'{"Item": "item's value"}'

That is valid json. You were missing the " around Item

---

In addition:

[WebMethod]
[ScriptMethod(UseHttpGet = true, ResponseFormat = ResponseFormat.Json)]
public string Test(string Item)
{
    JavaScriptSerializer js = new JavaScriptSerializer();
    string strJSON = js.Serialize(Item);
    return strJSON;
}

should be:

[WebMethod]
[ScriptMethod(ResponseFormat = ResponseFormat.Json)]
public string Test(string Item)
{
    return Item;
}

You don’t need to serialize that string.