<XmlSchemaProvider("MySchema")> _
Public Class SongStream
Implements IXmlSerializable
Private Const ns As String = "http://demos.Contoso.com/webservices"
Private filePath As String
Public Sub New()
End Sub
Public Sub New(ByVal filePath As String)
Me.filePath = filePath
End Sub
' This is the method named by the XmlSchemaProviderAttribute applied to the type.
Public Shared Function MySchema(ByVal xs As XmlSchemaSet) As XmlQualifiedName
' This method is called by the framework to get the schema for this type.
' We return an existing schema from disk.
Dim schemaSerializer As New XmlSerializer(GetType(XmlSchema))
Dim xsdPath As String = Nothing
' NOTE: replace SongStream.xsd with your own schema file.
xsdPath = System.Web.HttpContext.Current.Server.MapPath("SongStream.xsd")
Dim s As XmlSchema = CType(schemaSerializer.Deserialize(New XmlTextReader(xsdPath)), XmlSchema)
xs.XmlResolver = New XmlUrlResolver()
xs.Add(s)
Return New XmlQualifiedName("songStream", ns)
End Function
Sub WriteXml(ByVal writer As System.Xml.XmlWriter) Implements IXmlSerializable.WriteXml
' This is the chunking code.
' ASP.NET buffering must be turned off for this to work.
Dim bufferSize As Integer = 4096
Dim songBytes(bufferSize) As Char
Dim inFile As FileStream = File.Open(Me.filePath, FileMode.Open, FileAccess.Read)
Dim length As Long = inFile.Length
' Write the file name.
writer.WriteElementString("fileName", ns, Path.GetFileNameWithoutExtension(Me.filePath))
' Write the size.
writer.WriteElementString("size", ns, length.ToString())
' Write the song bytes.
writer.WriteStartElement("song", ns)
Dim sr As New StreamReader(inFile, True)
Dim readLen As Integer = sr.Read(songBytes, 0, bufferSize)
While readLen > 0
writer.WriteStartElement("chunk", ns)
writer.WriteChars(songBytes, 0, readLen)
writer.WriteEndElement()
writer.Flush()
readLen = sr.Read(songBytes, 0, bufferSize)
End While
writer.WriteEndElement()
inFile.Close()
End Sub
Function GetSchema() As System.Xml.Schema.XmlSchema Implements IXmlSerializable.GetSchema
Throw New System.NotImplementedException()
End Function
Sub ReadXml(ByVal reader As System.Xml.XmlReader) Implements IXmlSerializable.ReadXml
Throw New System.NotImplementedException()
End Sub
End Class