In this article I am going to explain What is Web
Service? How we can create and consume a Web Service?
What is Web Service?
Web
services are components on a Web server that a client application can call by
making HTTP requests across the Web. ASP.NET enables you to create custom Web
services or to use built-in application services, and to call these services
from any client application.
Web Services communicate by using standard web
protocols and data formats ie:
HTTP
XML
SOAP
Some term usually we see while using Web Services:
SOAP:
Simple Object Access Protocol. SOAP
is way by which method calls are translate into XML format and sent via HTTP.
WSDL: Web Service Description Language. WSDL contains every
detail regarding using web service and Method and Properties provided by web
service and URLs from which those methods can be accessed and Data Types used.
UDDI: Universal Description, Discovery and
Integration (UDDI) is a directory service where businesses can register and
search for Web services.
Discovery or
.Disco Files: The DISCO file typically points to a WSDL source that in turn
points to the actual Web Service. When one searches for the Web Services.
Now we will see how we
can create and consume Web Services in asp.net c#. Below is my Data Table in
Design mode from which I will fetch data using web service:

Image 1.
Script
of my Data Table is:
CREATE TABLE [dbo].[Employee](
[Emp_ID] [int]
IDENTITY(1,1) NOT NULL,
[Name]
[varchar](50) NULL,
[Designation]
[varchar](50) NULL,
[City] [varchar](50) NULL,
[State]
[varchar](50) NULL,
[Country]
[varchar](50) NULL,
CONSTRAINT [PK_Employee] PRIMARY
KEY CLUSTERED
(
[Emp_ID] ASC
)WITH (PAD_INDEX = OFF, STATISTICS_NORECOMPUTE = OFF,
IGNORE_DUP_KEY = OFF, ALLOW_ROW_LOCKS
= ON, ALLOW_PAGE_LOCKS = ON) ON
PRIMARY]
) ON [PRIMARY]
GO
Data in My Table is:

Image 2.
Now open Visual Studio
-> Select File -> New Web Site-> ASP.NET Web Service.

Image 3.
Now open Service.cs
inside App_Code folder to write your WebMethod like below:

Image 4.
App_Code/Service.cs is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Services;
using System.Data.SqlClient;
using System.Data;
using System.Xml;
[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 Service : System.Web.Services.WebService
{
public Service()
{
//Uncomment the following line if using designed components
//InitializeComponent();
}
[WebMethod]
public XmlElement
GetEmployeeSearchResult(string EMP_Name)
{
using (SqlConnection
con = new SqlConnection(@"Data Source=INDIA\MSSQLServer2k8; Initial
Catalog=EmployeeManagement; Uid=sa; pwd=india;"))
{
using (SqlCommand
cmd = new SqlCommand("SELECT * FROM EMPLOYEE WHERE Name like
@EMP_Name+'%'", con))
{
con.Open();
cmd.Parameters.AddWithValue("@EMP_Name",
EMP_Name);
cmd.ExecuteNonQuery();
SqlDataAdapter da = new
SqlDataAdapter(cmd);
DataSet ds = new DataSet();
da.Fill(ds);
con.Close();
XmlDataDocument xmldata = new
XmlDataDocument(ds);
XmlElement xmlElement = xmldata.DocumentElement;
return xmlElement;
}
}
}
}
Now time to check your Web Service So Run
your application:

Image 5.
Now click on your
Method name:

Image 6.

Image 7.
Now time to consume this web service so
create a new ASP.NET application

Image 8.
Now Right click on your application Solution
Explorer -> Add Web Reference

Image 9.
Type your web service
URL and click GO. After it Click on Add Reference Button:

Image 10.
Now my aspx is:
<%@ Page Language="C#"
AutoEventWireup="true"
CodeFile="Default.aspx.cs"
Inherits="_Default"
%>
<!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>Web Services In ASP.NET C#</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table style="border: solid 15px blue; width: 100%; vertical-align: central;">
<tr>
<td style="padding-left: 20px; padding-top: 20px; padding-bottom: 20px; background-color: skyblue;
text-align: center; font-family: Verdana; font-size: 20pt; color: red;">
Web
Services In ASP.NET C#
</td>
</tr>
<tr>
<td style="background-color: skyblue;
text-align: center;
font-family: Verdana;
font-size: 14pt;
color: red;">
<b>Enter Employee Name:</b>
<asp:TextBox ID="txtEmpName"
runat="server"></asp:TextBox>
<asp:Button ID="btnSearchEmployee"
runat="server"
Text="Search
Employee" OnClick="btnSearchEmployee_Click" />
</td>
</tr>
<tr>
<td>
<table style="width: 80%; text-align: center; vertical-align: central;">
<tr>
<td
style="text-align: left;">
<asp:GridView ID="GridViewEmployee"
runat="server"
AutoGenerateColumns="False"
Width="100%"
BackColor="White"
BorderColor="#3366CC"
BorderStyle="None"
BorderWidth="1px"
CellPadding="4">
<Columns>
<asp:BoundField DataField="Name"
HeaderText="Employee
Name" HeaderStyle-HorizontalAlign="Left">
<HeaderStyle HorizontalAlign="Left"></HeaderStyle>
</asp:BoundField>
<asp:BoundField DataField="Designation"
HeaderText="Designation"
HeaderStyle-HorizontalAlign="Left">
<HeaderStyle HorizontalAlign="Left"></HeaderStyle>
</asp:BoundField>
<asp:BoundField DataField="City"
HeaderText="City"
HeaderStyle-HorizontalAlign="Left">
<HeaderStyle HorizontalAlign="Left"></HeaderStyle>
</asp:BoundField>
<asp:BoundField DataField="State"
HeaderText="State"
HeaderStyle-HorizontalAlign="Left">
<HeaderStyle HorizontalAlign="Left"></HeaderStyle>
</asp:BoundField>
<asp:BoundField DataField="Country"
HeaderText="Country"
HeaderStyle-HorizontalAlign="Left">
<HeaderStyle HorizontalAlign="Left"></HeaderStyle>
</asp:BoundField>
</Columns>
<FooterStyle BackColor="#99CCCC"
ForeColor="#003399"
/>
<HeaderStyle BackColor="#003399"
Font-Bold="True"
ForeColor="#CCCCFF"
/>
<PagerStyle ForeColor="#003399"
HorizontalAlign="Left"
BackColor="#99CCCC"
/>
<RowStyle BackColor="White"
ForeColor="#003399"
/>
<SelectedRowStyle
BackColor="#009999"
Font-Bold="True"
ForeColor="#CCFF99"
/>
</asp:GridView>
</td>
</tr>
</table>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>
My aspx.cs is:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Data;
using System.Xml;
public partial class _Default :
System.Web.UI.Page
{
protected void
Page_Load(object sender, EventArgs e)
{
if (!IsPostBack)
{
BindEmployee("");
}
}
protected void
BindEmployee(string Emp_Name)
{
localhost.Service obj = new
localhost.Service();
DataSet ds = new DataSet();
XmlElement exElement =
obj.GetEmployeeSearchResult(Emp_Name);
if (exElement != null)
{
XmlNodeReader nodeReader = new XmlNodeReader(exElement);
ds.ReadXml(nodeReader, XmlReadMode.Auto);
GridViewEmployee.DataSource = ds;
GridViewEmployee.DataBind();
}
else
{
GridViewEmployee.DataSource = null;
GridViewEmployee.DataBind();
}
}
protected void
btnSearchEmployee_Click(object sender, EventArgs e)
{
BindEmployee(txtEmpName.Text);
}
}
Now run Your application:

Image 11.
Now enter some name and click on Search

Image 12.

Image 13.

Image 14.