Creating the ImageInfoProvider Web Service

The ImageInfoService class defines the ImageInfoProvider Web service.

Listing 6-6 shows the code for the ImageInfoService.asmx.vb class:

Listing 6-6: The ImageInfoService.asmx.vb File

 Imports System.Web.Services Imports System.Data.SqlClient Imports System.IO <System.Web.Services.WebService(Namespace:="http://tempuri.org/ImageInfoProvider/ImageInfoService")> _ Public Class ImageInfoService    Inherits System.Web.Services.WebService    Dim sqlConn As New SqlConnection    <System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()    components = New System.ComponentModel.Container    'Retrieving the connection string from a text file, Settings.txt.    Dim sqlConnectionString As String    Try    Dim sr As New StreamReader(Server.MapPath(".") & "\Settings.txt")    sqlConnectionString = sr.ReadLine    sr.Close()    Catch ex As Exception    'If there is error accessing the Settings.txt file    sqlConnectionString = "SERVER=localhost;UID=sa;PWD=sa;Initial Catalog=CoverDesigner"    End Try    'Try establishing connection to CoverDesigner database    Try    'Specifying the connection string for opening the connection    sqlConn.ConnectionString = sqlConnectionString    sqlConn.Open()    Catch ex As Exception    'Error establishing connection     End Try    End Sub    'This method returns information regarding the image whose information is     'requested by the Visio drawing in the cover designer application.    <WebMethod()> _    Public Function getImageInfo(ByVal imageCategoryId As Integer, ByVal imageFileName As String) As DataSet    Dim ds As New DataSet    Try    Dim sqlcmd As New SqlCommand("select * from images where imagecategoryId=" & _    imageCategoryId & " and imageFilename='" & imageFileName & "'", sqlConn)    Dim sqlda As New SqlDataAdapter(sqlcmd)    sqlda.Fill(ds)    Return ds    Catch ex As Exception    'Error in retrieving images information from database    'Return empty dataset    Return ds    End Try    End Function End Class 

 

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The above listing implements the getImageInfo method, which returns a dataset containing the information for the image selected by the end user .