Procedura: Utilizzare l'eredità in un servizio Web

Nell'esempio di codice seguente viene illustrato come utilizzare l'ereditarietà per creare un servizio Web per eseguire calcoli matematici. In questo esempio viene illustrata una delle linee guida spiegate nell'argomento, Progettare linee guida per i servizi Web XML creati utilizzando ASP.NET.

Esempio

<%@ WebService Language="C#" Class="Add" %>
using System;
using System.Web.Services;
abstract public class MathService : WebService 
{
   [WebMethod]
   abstract public float CalculateTotal(float a, float b);
}
public class Add : MathService 
{
   [WebMethod]
   override public float CalculateTotal(float a, float b)
   {
       return a + b;
   }
}
public class Subtract : MathService 
{
   [WebMethod]
   override public float CalculateTotal(float a, float b)
   {
       return a - b;
   }
}
public class Multiply : MathService 
{
   [WebMethod]
   override public float CalculateTotal(float a, float b)
   {
       return a * b;
   }
}
public class Divide : MathService 
{
   [WebMethod]
   override public float CalculateTotal(float a, float b)
   {
       if (b==0) 
          return -1;
       else
          return a / b;
   }
}

<%@ WebService Language="VB" Class="Add" %>
Imports System
Imports System.Web.Services
MustInherit Public Class MathService : Inherits WebService    
    <WebMethod> _
    Public MustOverride Function CalculateTotal(a As Single, _
                        b As Single) As Single
End Class
Public Class Add : Inherits MathService    
    <WebMethod> _
    Public Overrides Function CalculateTotal(a As Single, _
                     b As Single) As Single
        Return a + b
    End Function
End Class 
Public Class Subtract : Inherits MathService
    <WebMethod> _
    Public Overrides Function CalculateTotal(a As Single, _
                     b As Single) As Single
        Return a - b
    End Function
End Class 
Public Class Multiply : Inherits MathService
    <WebMethod> _
    Public Overrides Function CalculateTotal(a As Single, _
                     b As Single) As Single
        Return a * b
    End Function
End Class 
Public Class Divide : Inherits MathService
    <WebMethod> _
    Public Overrides Function CalculateTotal(a As Single, _
                     b As Single) As Single
        If b = 0 Then
            Return - 1
        Else
            Return a / b
        End If
    End Function
End Class

Vedere anche

Concetti

Linee guida di progrettazione per servizi Web XML creati tramite ASP.NET

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