ASP. NET create XML Web Service full contact (7)

Design Guidelines (2)

Many service requests over the Internet may affect the performance of your applications. When designing your XML Web Service, you can effectively use service requests by creating a method that aggregates relevant information. For example, assume that you have an XML Web Service used to retrieve information from a book. We can create a method to return all the information in a service request, instead of a separate method to retrieve the title, author, and publisher. One-time transmission of large pieces of information is more efficient than multiple transmission of small pieces of information.

The following code example explains how to organize the information to a single XML Web Service method.

[C #] <% @ WebService Language = "C #" Class = "DataService" %> Using System; Using System. Data; Using System. Data. SqlClient; Using System. Web. Services; Public class DataService { [WebMethod] Public DataSet GetTitleAuthors (){ SqlConnection myConnection = new SqlConnection ("Persist Security Info = False; Integrated Security = SSPI; server = localhost; database = pubs "); SqlDataAdapter myCommand1 = new SqlDataAdapter ("select * from Authors", myConnection ); SqlDataAdapter myCommand2 = new SqlDataAdapter ("select * from Titles", myConnection ); DataSet ds = new DataSet (); MyCommand1.Fill (ds, "Authors "); MyCommand2.Fill (ds, "Titles "); Return ds; } } [Visual Basic] <% @ WebService Language = "VB" Class = "DataService" %> Imports System Imports System. Data Imports System. Data. SqlClient Imports System. Web. Services Public Class DataService <WebMethod> _ Public Function GetTitleAuthors () As DataSet Dim myConnection As New SqlConnection ("Persist Security Info = False; Integrated Security = SSPI; server = localhost; database = pubs ") Dim myCommand1 As New SqlDataAdapter ("select * from Authors", myConnection) Dim myCommand2 As New SqlDataAdapter ("select * from Titles", myConnection) Dim ds As New DataSet () MyCommand1.Fill (ds, "Authors ") MyCommand2.Fill (ds, "Titles ") Return ds End Function End Class

When designing your XML Web Service, make sure to use standard object-oriented programming operations. Use encapsulation to hide implementation details. For more complex XML Web Services, you can use inheritance and Polymorphism to re-use code and simplify your design.

The following code example shows how to use inheritance to create an XML Web Service that executes mathematical computing.

[C #] <% @ 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; } } [Visual Basic] <% @ 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