Web Services in Visual Basic

Web Services in Visual Basic

For completeness, this chapter includes a Visual Basic version of the QuoteService. It's in a separate project named QuoteServiceVB. The file name is QuoteServiceVB.asmx. Listing 19-2 shows the Visual Basic code for the service. Listing 19-3 shows the Visual Basic code for the QuotesCollection.VB utility class.

Listing 19-2

Imports System Imports System.Data Imports System.Configuration Imports System.Web Imports System.Web.Security Imports System.Web.UI Imports System.Web.UI.WebControls Imports System.Web.UI.WebControls.WebParts Imports System.Web.UI.HtmlControls Imports System.IO <Serializable()> _ Public Class QuotesCollection : Inherits DataTable     Public Sub QuotesCollection()     End Sub     Public Sub Synthesize()         Me.TableName = "Quotations"         Dim dr As DataRow         Columns.Add(New _            DataColumn("Quote", GetType(String)))         Columns.Add(New _            DataColumn("OriginatorLastName", GetType(String)))         Columns.Add(New _             DataColumn("OriginatorFirstName", GetType(String)))         dr = Me.NewRow()         dr(0) = _            "Imagination is more important than knowledge."         dr(1) = "Einstein"         dr(2) = "Albert"         Rows.Add(dr)         dr = Me.NewRow()         dr(0) = _            "Assume a virtue, if you have it not"         dr(1) = "Shakespeare"         dr(2) = "William"         Me.Rows.Add(dr)         dr = Me.NewRow()               dr(0) = _            "A banker is a fellow who lends you his " + _            "umbrella when the sun is shining, but wants " + _            "it back the minute it begins to rain."         dr(1) = "Twain"         dr(2) = "Mark"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "A man cannot be comfortable without " + _         "his own approval."         dr(1) = "Twain"         dr(2) = "Mark"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Beware the young doctor and the " + _         "old barber"         dr(1) = "Franklin"         dr(2) = "Benjamin"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Reality is merely an illusion, " + _         "albeit a very persistent one."         dr(1) = "Einstein"         dr(2) = "Albert"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Beer has food value, but food has " + _         "no beer value"         dr(1) = "Sticker"         dr(2) = "Bumper"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Research is what I'm doing when I " + _         "don() 't know what I'm doing"         dr(1) = "Von Braun"         dr(2) = "Wernher""         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Whatever is begun in anger ends in shame"         dr(1) = "Franklin"         dr(2) = "Benjamim"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "We think in generalities, but " + _         "we live in details"         dr(1) = "Whitehead"         dr(2) = "Alfred North"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "Every really new idea looks crazy " + _         "at first."         dr(1) = "Whitehead"         dr(2) = "Alfred North"         Me.Rows.Add(dr)         dr = Me.NewRow()         dr(0) = "The illiterate of the 21st century will " + _         "not be those who cannot read and write, but those " + _         "who cannot learn, unlearn, and relearn."         dr(1) = "Whitehead"         dr(2) = "Alfred North"         Me.Rows.Add(dr)     End Sub End Class

Listing 19-3

Imports System Imports System.Web Imports System.Data Imports System.Web.Services Imports System.Web.Services.Protocols Imports System.Web.Caching Public Structure Quote     Public _strQuote As String     Public _strOriginatorLastName As String     Public _strOriginatorFirstName As String     Public Sub New(ByVal strQuote As String, _             ByVal strOriginatorLastName As String, _             ByVal strOriginatorFirstName As String)         _strQuote = strQuote         _strOriginatorLastName = strOriginatorLastName         _strOriginatorFirstName = strOriginatorFirstName     End Sub End Structure <WebService(Namespace:="http://tempuri.org/")> _ <WebServiceBinding(ConformsTo:=WsiProfiles.BasicProfile1_1)> _ Public Class QuoteServiceVB     Inherits System.Web.Services.WebService     Function LoadQuotes() As QuotesCollection         Dim quotesCollection As QuotesCollection         Dim ctx As HttpContext         ctx = HttpContext.Current         Dim o As Object         o = ctx.Cache("quotesCollection")         quotesCollection = CType(o, QuotesCollection)         If quotesCollection Is Nothing Then             quotesCollection = New QuotesCollection()             Dim strAppPath As String             strAppPath = Server.MapPath("")             Dim strFilePathXml As String             strFilePathXml = _                strAppPath ' _                "\\app_data\\QuotesCollection.xml"             Dim strFilePathSchema As String             strFilePathSchema = _                strAppPath ' _                "\\app_data\\QuotesCollection.xsd"             quotesCollection.ReadXmlSchema(strFilePathSchema)             quotesCollection.ReadXml(strFilePathXml)             Dim cacheDependency As CacheDependency             cacheDependency = New CacheDependency(strFilePathXml)             ctx.Cache.Insert("quotesCollection", _                  quotesCollection, _                  cacheDependency, _                  Cache.NoAbsoluteExpiration, _                  Cache.NoSlidingExpiration, _                  CacheItemPriority.Default, _                Nothing)         End If         Return quotesCollection     End Function     Public Sub QuoteService()     End Sub     <WebMethod()> _     Public Function HelloWorld() As String         Return "Hello World"     End Function     <WebMethod()> _     Public Function GetAQuote() As Quote         Dim quotesCollection As QuotesCollection         quotesCollection = Me.LoadQuotes()         Dim nNumQuotes As Integer         nNumQuotes = quotesCollection.Rows.Count         Dim random As Random         random = New Random()         Dim nQuote As Integer         nQuote = random.Next(nNumQuotes)         Dim dataRow As DataRow         dataRow = quotesCollection.Rows(nQuote)         Dim quote As Quote         quote = New Quote(CType(dataRow("Quote"), String), _             CType(dataRow("OriginatorLastName"), String), _             CType(dataRow("OriginatorFirstName"), String))         Return quote     End Function     <WebMethod()> _     Public Sub AddQuote(ByVal quote As Quote)         Dim quotesCollection As QuotesCollection         quotesCollection = Me.LoadQuotes()         Dim dr As DataRow         dr = quotesCollection.NewRow()         dr(0) = quote._strQuote         dr(1) = quote._strOriginatorLastName         dr(2) = quote._strOriginatorFirstName         quotesCollection.Rows.Add(dr)         Dim strAppPath As String         strAppPath = Server.MapPath("")         Dim strFilePathXml As String         strFilePathXml = _            strAppPath + "\\app_data\\QuotesCollection.xml"         Dim strFilePathSchema As String         strFilePathSchema = _            strAppPath + "\\app_data\\QuotesCollection.xsd"         quotesCollection.WriteXmlSchema(strFilePathSchema)         quotesCollection.WriteXml(strFilePathXml)     End Sub     <WebMethod()> _     Public Function GetAllQuotes() As DataSet         Dim quotesCollection As QuotesCollection         quotesCollection = LoadQuotes()         Dim dataSet As DataSet         dataSet = New DataSet()         dataSet.Tables.Add(quotesCollection)         Return dataSet     End Function End Class