Invoking Web Service written in ASP.NET through jQuery which returns data in JSON Format

This post explains how we can make an Ajax Call in jQuery and invoke a Web Service that has been written in ASP.NET. Also the Web Service is going to return data in JSON Format i.e. Javascript Object Notation which is nothing but an implementation of DataDictionary concept. By default the web service written in ASP.NET will return data in XML Format. But JSON provides a faster way to get and parse data through jQuery. In this example, we will invoke a method written in Web Service by jQuery. The following steps are to be performed:

Step 1: Host the Web Service written in ASP.NET

We have to host the web service that has been written in ASP.NET. The following code shows a typical web service written in ASP.NET

using System;

using System.Collections.Generic;

using System.Linq;

using System.Web;

using System.Web.Services;

using System.Data.SqlClient;

using System.Web.Script.Services;

using System.Web.Services.Protocols;

///

/// Summary description for ProfessionalWebService

///

[WebService(Namespace = "http://tempuri.org/")]

[WebServiceBinding(ConformsTo = WsiProfiles.BasicProfile1_1)]

// To allow this Web Service to be called from script, using ASP.NET AJAX, uncomment the following line.

[System.Web.Script.Services.ScriptService]

public class ProfessionalWebService : System.Web.Services.WebService {

    public ProfessionalWebService () {

        //Uncomment the following line if using designed components

        //InitializeComponent();

    }

   [WebMethod]

    [ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)]

    public int ReturnNumber()

    {

        return 100;

    }

}

In the above example we can see that the web service contains only one method with the name "ReturnNumber" and it returns only integer. But as the web service will return the data in XML format, we are using [ScriptMethod(UseHttpGet = false, ResponseFormat = ResponseFormat.Json)] preceding the web method so that the data is returned in the JSON Format.

Step 2: Invoking the Web Service through jQuery

Once the Web service is hosted then we can invoke through jQuery. The following code shows how the web method is invoked through jQuery on a click of a button.

$('#btnWebService1').click(function (e) {

                     e.preventDefault();

                     $.ajax({

                         type: "POST",

                         url:"http://localhost/Web/Lovely.asmx/ReturnNumber",

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

                         dataType: "json",

                         success: function (msg) {

                             var t = msg.d;

                         

   $('#TextBox1').val(t.toString());

                         },

                         error: function () {

                             alert("OOPs!!!. Some error occurred while calling");

                         }

                     });

                 });

So, through the above example, you can see how we can invoke web services through jQuery and return data in JSON Format. Do try it for yourself and share your thoughts with me.

Happy coding. Keep on trying.