<%@ WebService Language="vb" Class="Caller_Id" %>
Imports System
Imports System.Data
Imports System.Data.SqlClient
Imports System.Web.Services
Imports System.Configuration
'// When declaring a namespace for your Web service
'// Choose something that will be a unique identifier
'// Notice how I used the domain name that I own
<WebService(Namespace:="www.allpaul.com")> _
Public Class Caller_Id
<WebMethod> Public Function Get_Callers() As Dataset
try
Dim myConnection As SqlConnection
Dim myCommand As SqlDataAdapter
myConnection = New _
SqlConnection(ConfigurationSettings.AppSettings("MyDSN"))
myCommand = New _
SqlDataAdapter("sp_GetCallers", myConnection)
myCommand.SelectCommand.CommandType = _
CommandType.StoredProcedure
myConnection.Open()
Dim myDataSet As New DataSet()
myCommand.Fill(myDataSet, "tbl_Caller_Id")
myConnection.Close
Return myDataSet
catch exp As Exception
Return nothing
End try
End Function
<WebMethod> Public Sub Delete_Caller(Caller_Id as Integer)
Dim myConnection As _
New SqlConnection(ConfigurationSettings.AppSettings("MyDSN"))
Dim myCommand As _
New SqlCommand("sp_DeleteCaller", myConnection)
myCommand.CommandType = CommandType.StoredProcedure
Dim parameterCaller_Id As _
New SqlParameter("@Caller_ID", SqlDbType.Int, 4)
parameterCaller_Id.Value = Caller_Id
myCommand.Parameters.Add(parameterCaller_Id)
myConnection.Open()
myCommand.ExecuteNonQuery()
myConnection.Close()
End Sub
End Class
Any method in a class can be called via a Web service request as long as <WebMethod> appears before the declaration of the method.
This service has two WebMethods:
Get_Callers
This method accepts no parameters and returns all the callers from the database as a dataset to the page that calls the method. It uses a stored procedure, sp_GetCallers, that simply retrieves all the records from the table tbl_Caller_id.
CREATE PROCEDURE sp_GetCallers
AS
Select * From tbl_Caller_Id Order By Call_Date
GO
Delete_Caller
This method used to delete a specific caller from the database. The method expects an integer Caller_ID and uses the stored procedure sp_DeleteCaller passing it the input parameter Caller_ID.
CREATE PROCEDURE sp_DeleteCaller
(
@Caller_ID int
)
AS
Delete From tbl_Caller_Id WHERE ID = @Caller_ID
GO
To test the service, navigate to the URL using any Web browser. Conveniently, Web services are served to Web browsers as html interfaces. So, if you navigate to the service you should see a page similar to the following screenshot.
And, clicking on the links named for each of the services Web methods allows you to invoke the method (if parameters are expected you will be prompted to provide them) and view the results.
Get_Callers:
The resulting xml from invoking the method
Because the Delete_Caller method is expecting a parameter (Caller_ID) the service asks for the Caller_ID in the form of a input form element.
Now that we have a fully functioning Web service, all that's left is to build an ASP.NET page to consume the service. I'll do that in part 3.
