Programming Microsoft Visual Basic .NET/Programming Microsoft Visual Basic .NET (Microsoft Press)(X08-78517)(2002).bin/setup/vbnet/11 object serialization/serializationdemo/module1.vb

Text File | 2002-03-20 | 10.5 KB | 315 lines

Imports System.IO
Imports System.Runtime.Serialization
Imports System.Runtime.Serialization.Formatters.Binary
Imports System.Runtime.Serialization.Formatters.Soap

Module MainModule

    Sub Main()
        ' Run one of the Textxxxx procedures below by uncommenting only one statement

        'TestSaveArray()
        'TestLoadArray()
        'TestSoapSerialization()
        'TestSerializableClass()
        'TestSerializableGraph()
        'TestCloneObject()
        'TestCustomSerialization()
        'TestCustomSerialization2()
        'TestIDeserializationCallback()

        ' These statements are usuful when running inside Visual Studio.NET
        Console.WriteLine("")
        Console.WriteLine(">>> Press Enter to terminate the program <<<")
        Console.ReadLine()
    End Sub

    ' this procedure tests the serialization of an array of integer

    Sub TestSaveArray()
        ' Create an array of integers.
        Dim arr() As Integer = {1, 2, 4, 8, 16, 32, 64, 128, 256}

        ' Open a file stream for output.
        Dim fs As FileStream = New FileStream("c:\powers.dat", FileMode.Create)
        ' Create a binary formatter for this stream.
        Dim bf As New BinaryFormatter()

        ' Serialize the array to the file stream, and flush the stream.
        bf.Serialize(fs, arr)
        fs.Close()
    End Sub

    ' this procedure deserializes an array of integers

    Sub TestLoadArray()
        ' Open a file stream for input.
        Dim fs As FileStream = New FileStream("c:\powers.dat", FileMode.Open)
        ' Create a binary formatter for this stream.
        Dim bf As New BinaryFormatter()

        ' Deserialize the contents of the file stream into an Integer array.
        Dim arr() As Integer
        ' Deserialize returns an object that must be coerced.
        arr = DirectCast(bf.Deserialize(fs), Integer())

        ' Display the result.
        Dim n As Integer
        For Each n In arr
            Console.Write(n.ToString & " ")
        Next
        Console.WriteLine("")
    End Sub

    ' these reusable procedure save and load data in SOAP format

    ' Serialize an object to file in SOAP format.
    Sub SaveSoapData(ByVal path As String, ByVal o As Object)
        ' Open a file stream for output.
        Dim fs As FileStream = New FileStream(path, FileMode.Create)
        ' Create a SOAP formatter for this stream.
        Dim sf As New SoapFormatter(Nothing, New StreamingContext(StreamingContextStates.File))
        ' Serialize the array to the file stream, and close the stream.
        sf.Serialize(fs, o)
        fs.Close()
    End Sub

    ' Deserialize an object from a file in SOAP format.
    Function LoadSoapData(ByVal path As String) As Object
        ' Open a file stream for input.
        Dim fs As FileStream = New FileStream(path, FileMode.Open)
        ' Create a SOAP formatter for this stream.
        Dim sf As New SoapFormatter(Nothing, New StreamingContext(StreamingContextStates.File))

        ' Deserialize the contents of the file stream into an object.
        LoadSoapData = sf.Deserialize(fs)
        ' close the stream.
        fs.Close()
    End Function

    ' this procedure tests the reusable routines above

    ' An example that uses the above routines.
    Sub TestSoapSerialization()
        ' Create a hashtable object and fill it with some data.
        Dim ht As New Hashtable()
        ht.Add("One", 1)
        ht.Add("Two", 2)
        ht.Add("Three", 3)

        ' Save the hash table to disk in SOAP format.
        SaveSoapData("c:\hashtbl.xml", ht)

        ' Reload the file contents into another HashTable object.
        Dim ht2 As Hashtable
        ht2 = CType(LoadSoapData("c:\hashtbl.xml"), Hashtable)

        ' Display values.
        Dim de As DictionaryEntry
        For Each de In ht2
            Console.WriteLine("Key=" & de.Key.ToString & _
                "   Value=" & de.Value.ToString)
        Next
    End Sub

    ' this procedure tests the <serializable> and <notserialized> attributes

    Sub TestSerializableClass()
        Dim al As New ArrayList()
        al.Add(New Person("Joe", "Doe", #1/12/1960#))
        al.Add(New Person("John", "Smith", #3/6/1962#))
        al.Add(New Person("Ann", "Doe", #10/4/1965#))

        ' Save the ArrayList to disk in SOAP format.
        SaveSoapData("c:\hashtbl.xml", al)

        ' Reload the file contents into another ArrayList object.
        Dim al2 As ArrayList
        al2 = DirectCast(LoadSoapData("c:\hashtbl.xml"), ArrayList)

        ' Display values.
        Dim p As Person
        For Each p In al2
            Console.WriteLine(p.FirstName & " " & p.LastName & " (" & p.Age & ")")
        Next
    End Sub

    ' this procedure tests the serialization of an object graph

    Sub TestSerializableGraph()
        ' Create three Person objects.
        Dim p1 As New Person("Joe", "Doe", #1/12/1960#)
        Dim p2 As New Person("John", "Smith", #3/6/1962#)
        Dim p3 As New Person("Ann", "Doe", #10/4/1965#)
        ' Define the relationship between two of them.
        p2.Spouse = p3
        p3.Spouse = p2

        ' Load them into an ArrayList object.
        Dim al As New ArrayList()
        al.Add(p1)
        al.Add(p2)
        al.Add(p3)

        ' Save the hash table to disk in XML format
        SaveSoapData("c:\hashtbl.xml", al)

        ' Reload the file contents into another HashTable object.
        Dim al2 As ArrayList
        al2 = DirectCast(LoadSoapData("c:\hashtbl.xml"), ArrayList)

        ' Display values.
        Dim p As Person
        For Each p In al2
            Console.WriteLine(p.FirstName & " " & p.LastName & " (" & p.Age & ")")
            If Not (p.Spouse Is Nothing) Then
                ' Show the spouse's name, if there is one.
                Console.WriteLine("   Spouse of " & p.Spouse.FirstName)
            End If
        Next
    End Sub

    ' this procedure tests object cloning

    Sub TestCloneObject()
        ' create an object graph
        Dim p1 As New Person("Joe", "Doe", #1/2/1960#)
        Dim p2 As New Person("Ann", "Smith", #3/4/1965#)
        p1.Spouse = p2
        p2.Spouse = p1

        ' Clone it
        Dim q1 As Person = DirectCast(CloneObject(p1), Person)
        Dim q2 As Person = q1.Spouse
        ' Prove that properties were copied correctly.
        Console.WriteLine(q1.FirstName & " " & q1.LastName)
        Console.WriteLine(q2.FirstName & " " & q2.LastName)
        Console.WriteLine("P1 is Q1 = {0}", p1 Is q1)
        Console.WriteLine("P2 is Q2 = {0}", p2 Is q2)
    End Sub

    ' a reusable function that does object cloning

    Function CloneObject(ByVal obj As Object) As Object
        ' Create a memory stream and a formatter.
        Dim ms As New System.IO.MemoryStream(1000)
        Dim bf As New BinaryFormatter(Nothing, New StreamingContext(StreamingContextStates.Clone))
        ' Serialize the object into the stream.
        bf.Serialize(ms, obj)
        ' Position streem pointer back to first byte.
        ms.Seek(0, SeekOrigin.Begin)
        ' Deserialize into another object.
        CloneObject = bf.Deserialize(ms)
        ' release memory.
        ms.Close()
    End Function

    ' this procedure tests the ISerializable interface

    Sub TestCustomSerialization()
        ' Create a compact array of Double, whose DefaultValue is 1.
        Dim ca As New CompactDoubleArray()
        ca.DefaultValue = 1
        ' Add some elements (including some default values).
        ca.Add(1)
        ca.Add(2)
        ca.Add(3)
        ca.Add(1)
        ca.Add(4)
        ca.Add(5)
        ca.Add(1)
        ' Serialize the array.
        SaveSoapData("c:\compact.xml", ca)

        ' Read it back.
        Dim ca2 As CompactDoubleArray
        ca2 = DirectCast(LoadSoapData("c:\compact.xml"), CompactDoubleArray)

        ' Print its contents.
        Dim o As Object
        For Each o In ca2
            Console.Write(o.ToString & " ")
        Next
        Console.WriteLine("")
    End Sub

    ' this procedure is identical to previous one, but it uses CompactDoubleArray2

    Sub TestCustomSerialization2()
        ' Create a compact array of Double, whose DefaultValue is 1.
        Dim ca As New CompactDoubleArray2()
        ca.DefaultValue = 1
        ' Add some elements (including some default values).
        ca.Add(1)
        ca.Add(2)
        ca.Add(3)
        ca.Add(1)
        ca.Add(4)
        ca.Add(5)
        ca.Add(1)

        ' Serialize the array to a memory stream (to prove it isn't compat
        SaveSoapData("c:\compact.xml", ca)

        ' Read it back.
        Dim ca2 As CompactDoubleArray2
        ca2 = DirectCast(LoadSoapData("c:\compact.xml"), CompactDoubleArray2)

        ' Print its contents.
        Dim o As Object
        For Each o In ca2
            Console.Write(o.ToString & " ")
        Next
        Console.WriteLine("")

        ' Serialize the array to a memory stream (to prove it isn't compacted)

        ' Create the memory stream
        Dim ms As New MemoryStream(10000)
        ' Create a binary formatter for this stream
        Dim bf As New BinaryFormatter()
        ' serialize the CompactArrayDouble object to the stream
        bf.Serialize(ms, ca)

        ' rewind the memory stream and read its contents back into CA2
        ms.Seek(0, SeekOrigin.Begin)
        ca2 = DirectCast(bf.Deserialize(ms), CompactDoubleArray2)
        ' close the stream
        ms.Close()

        For Each o In ca2
            Console.Write(o.ToString & " ")
        Next
        Console.WriteLine("")
    End Sub

    ' this procedure tests IDeserializationCallback interface

    Sub TestIDeserializationCallback()
        ' Create a compact array of Point objects.
        Dim ca As New CompactPointArray()
        ' Add some elements (including some (0,0) points).
        ca.Add(New Point(1, 3))
        ca.Add(New Point(0, 0))
        ca.Add(New Point(3, 5))
        ca.Add(New Point(1, 6))
        ca.Add(New Point(0, 0))
        ca.Add(New Point(4, 8))
        ca.Add(New Point(0, 0))
        ' Serialize it.
        SaveSoapData("c:\points.xml", ca)

        ' Read it back.
        Dim ca2 As CompactPointArray
        ca2 = DirectCast(LoadSoapData("c:\Points.xml"), CompactPointArray)

        ' Print its contents.
        Dim o As Object
        For Each o In ca2
            Console.Write(o.ToString & " ")
        Next
        Console.WriteLine("")
    End Sub

End Module