Web Service Example
Any application can have a Web Service component.
Web Services can be created regardless of programming language.
A Web Service Example
In the following example we will use ASP.NET to create a simple Web Service
that converts the temperature from Fahrenheit to Celsius, and vice versa:
<%@ WebService Language="VBScript" Class="TempConvert" %>
Imports System
Imports System.Web.Services
Public Class TempConvert :Inherits WebService
<WebMethod()> Public Function FahrenheitToCelsius
(ByVal Fahrenheit As String) As String
dim fahr
fahr=trim(replace(Fahrenheit,",","."))
if fahr="" or IsNumeric(fahr)=false then return "Error"
return ((((fahr) - 32) / 9) * 5)
end function
<WebMethod()> Public Function CelsiusToFahrenheit
(ByVal Celsius As String) As String
dim cel
cel=trim(replace(Celsius,",","."))
if cel="" or IsNumeric(cel)=false then return "Error"
return ((((cel) * 9) / 5) + 32)
end function
end class
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This document is saved as an .asmx file. This is the ASP.NET file extension for XML Web
Services.
Example Explained
Note: To run this example, you will need a .NET server.
The first line in the example states that this is a Web Service, written in VBScript, and
has the
class name "TempConvert":
<%@ WebService Language="VBScript" Class="TempConvert" %>
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The next lines import the namespace "System.Web.Services" from the .NET
framework:
Imports System
Imports System.Web.Services
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The next line defines that the "TempConvert" class is a WebService
class type:
Public Class TempConvert :Inherits WebService
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The next steps are basic VB programming. This application has two functions.
One to convert from Fahrenheit to Celsius, and one to convert from Celsius to
Fahrenheit.
The only difference from a normal
application is that this function is defined as a "WebMethod()".
Use "WebMethod()"
to convert the functions in your application into web services:
<WebMethod()> Public Function FahrenheitToCelsius
(ByVal Fahrenheit As String) As String
dim fahr
fahr=trim(replace(Fahrenheit,",","."))
if fahr="" or IsNumeric(fahr)=false then return "Error"
return ((((fahr) - 32) / 9) * 5)
end function
<WebMethod()> Public Function CelsiusToFahrenheit
(ByVal Celsius As String) As String
dim cel
cel=trim(replace(Celsius,",","."))
if cel="" or IsNumeric(cel)=false then return "Error"
return ((((cel) * 9) / 5) + 32)
end function
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Then, end the class:
Publish the .asmx file on a server with .NET
support, and you will have your first working Web Service.
Look at our
example Web Service
ASP.NET Automates the Process
With ASP.NET, you do not have to write your own WSDL and SOAP documents.
If you look closer at our example Web Service, you will see that ASP.NET
has automatically created a
WSDL and
SOAP
request.
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