Simple Web Service - Fahrenheit to Celsius in VB .NET

This tutorial will show how we can create a Web Service that will allow us to convert from Fahrenheit to Celsius, or vice versa. VB version.

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Web Services allow you to use applications in your Web Project. In this demonstration, we will show how we can easily implement an application into our Web Project. We will write two simple methods that will enable us to convert Fahrenheit into Celsius, and vice versa. The methods will be the Web Service, and theoretically, be stored on a different web server than our Web Project that is using it.

First, we start off with a Web Service Porject in Visual Studio .NET
Then we will add the logic to the App_Code folder, in the .vb file:

Imports System.Web Imports System.Web.Services Imports System.Web.Services.Protocols <WebService(Namespace:="http://tempuri.org/")> _ <WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _ <Global.Microsoft.VisualBasic.CompilerServices.DesignerGenerated()> _ Public Class Service Inherits System.Web.Services.WebService <WebMethod()> _ Public Function HelloWorld() As String Return "Hello World" End Function <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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Here, there are three methods. One is the simple Hello World method, which will retrieve a string when called. The other two will convert a number into either Fahrenheit or Celsius, depending on which method is called.
The Service.asmx file will look something like this:

<%@ WebService Language="vb" CodeBehind="~/App_Code/Service.vb" Class="Service" %>

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We now need a form to call the Web Service, as well as send the number to convert. For this, we create a web form and allow the user to either convert from Fahrenheit to Celsius, or Celsius to Fahrenheit.
The ASPX page should look something like the following:

<form target="_blank" action="Service.asmx/FahrenheitToCelsius" method="POST"> <table> <tr> <td>Fahrenheit to Celsius:</td> <td><input class="frmInput" type="text" size="30" name="Fahrenheit"></td> </tr> <tr> <td></td> <td align="right"> <input type="submit" value="Submit" class="button"></td> </tr> </table> </form> <form target="_blank" action="Service.asmx/CelsiusToFahrenheit" method="POST"> <table> <tr> <td>Celsius to Fahrenheit:</td> <td><input class="frmInput" type="text" size="30" name="Celsius"></td> </tr> <tr> <td></td> <td align="right"> <input type="submit" value="Submit" class="button"></td> </tr> </table> </form>

Looking for the C#.NET 2005 Version? Click Here!

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