Sending JSON object successfully to ASP.NET WebMethod, using jQuery

When using AJAX.NET I always make the input parameter just a plain old object and then use the javascript deserializer to covert it to whatever type I want. At least that way you can debug and see what type of object the web method in is recieving.

You need to convert your object to a string when using jQuery

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
        <asp:ScriptManager ID="sm" runat="server" EnablePageMethods="true">
            <Scripts>
                <asp:ScriptReference Path="~/js/jquery.js" />
            </Scripts>
        </asp:ScriptManager>
        <div></div>
    </form>
</body>
</html>
<script type="text/javascript" language="javascript">
    var items = [{ compId: "1", formId: "531" },
        { compId: "2", formId: "77" },
        { compId: "3", formId: "99" },
        { status: "2", statusId: "8" },
        { name: "Value", value: "myValue"}];

        //Using Ajax.Net Method
        PageMethods.SubmitItems(items,
            function(response) { var results = response.d; },
            function(msg) { alert(msg.d) },
            null);

        //using jQuery ajax Method
        var options = { error: function(msg) { alert(msg.d); },
                        type: "POST", url: "WebForm1.aspx/SubmitItems",
                        data: {"items":items.toString()}, // array to string fixes it *
                        contentType: "application/json; charset=utf-8",
                        dataType: "json",
                        async: false, 
                        success: function(response) { var results = response.d; } }; 
        jQuery.ajax(options);
</script>

And the Code Behind

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Web.Script.Serialization;
using System.Web.Script.Services;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace CustomEquip
{
    [ScriptService]
    public partial class WebForm1 : System.Web.UI.Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {

        }
        [WebMethod]
        public static void SubmitItems(object items)
        {
            //break point here
            List<object> lstItems = new JavaScriptSerializer().ConvertToType<List<object>>(items);
        }
    }
}

In your example, it should work if your data parameter is:

data: "{'items':" + JSON.stringify(items) + "}"

Keep in mind that you need to send a JSON string to ASP.NET AJAX. If you specify an actual JSON object as jQuery's data parameter, it will serialize it as &k=v?k=v pairs instead.

It looks like you've read it already, but take another look at my example of using a JavaScript DTO with jQuery, JSON.stringify, and ASP.NET AJAX. It covers everything you need to make this work.

Note: You should never use JavaScriptSerializer to manually deserialize JSON in a "ScriptService" (as suggested by someone else). It automatically does this for you, based on the specified types of the parameters to your method. If you find yourself doing that, you are doing it wrong.

Tags:

Javascript

Asp.Net

Ajax

Jquery

Json

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