Skip to main content

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.



Comments

manoj said…
Thanks for this post .Please post more tutorials on Json, Jsonp and Odata
June 24, 2013 at 1:23 AM
Post a Comment

Popular posts from this blog

How to use QueryExtenderControl in ASP.NET with LINQ

Queryextender control is a control that helps in doing actions like filtration, searching, sorting etc. on the LINQ Data source with few steps. In fact we don’t have to write any code with this. Screenshot given below is just an example that can easily be achieved through this control. In the above screenshot, we can see that there is a GridView Control that has been binded to a LINQData Source Control. And we have a DropDownlistBox that is also binded to another LINQData Source Control and displaying only grouped jobs. The GridView display all the employees who are matching the Job Parameter. This is done through QueryExtender Control. Also we can search for any name in the employee name's through Query Extender control. The code in the HTML goes like: < form id ="form1" runat ="server">     < div >         Select Job: < asp : DropDownList ID ="Job" runat ="server" DataSourceID ="LinqDataSource2...
Post a Comment
Read more

Using GUID or UniqueIdentifiers in SQL Server

In order to differentiate between two rows, we normally use primary keys or identity values which may be same across two tables. In order to overcome this problem we can use a special type named "GUID" . Its a hexadecimal number (Base 16) and the advantage is  that they are unique across all databases and tables.  In SQL Server the same concept is implemented through UNIQUEIDENTIFIER  data type. In order to generate a new value, we use the NEWID() function. For e.g.  a. Creating a table that uses the UNIQUEIDENTIFIER datatype Create table Test ( Empno uniqueidentifier, Ename varchar(20) ) b. Inserting rows in the tables with the use of NEWID() function insert into Test values (newId(),'ABC') insert into Test values (newid(),'XYZ') insert into test values (newid(),'MNO') c. Selecting the rows from the table. Select * from test  Empno                             ...
Post a Comment
Read more

How to Delete Record through Knex.

This post is all about of deleting records through KNEX ORM in Nodejs. The following code shows how to achieve this: knex("depts").where("deptno","50").del() .then(function (count) {     console.log(count); }) .finally(function () {     knex.destroy(); }); The above code deletes a record from a table "Depts" where Deptno = 50. It has a "then" Promise attached that will show how many records were deleted with this command. Also "finally" is the method that will always execute and will close the KNEX connection. Happy Coding !!!
Post a Comment
Read more