samples/snippets/visualbasic/VS_Snippets_CFX/datamemberattribute/vb/overview.vb - main - aprogrammer/dotnet-docs

samples/snippets/visualbasic/VS_Snippets_CFX/datamemberattribute/vb/overview.vb
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Format codes based on .editorconfig, Part 4 (#18853)
08 июн 2020, 22:49
08 июн 2020, 22:497e34efc
'<snippet0>
Imports System.Collections
Imports System.IO
Imports System.Runtime.Serialization
Imports System.Xml

' You must apply a DataContractAttribute or SerializableAttribute
' to a class to have it serialized by the DataContractSerializer.
<DataContract()> _
Class Person
    Implements IExtensibleDataObject

    Private LastNameValue As String

    ' Apply the DataMemberAttribute to fields (or properties) 
    ' that must be serialized.

    <DataMember()> _
    Public FirstName As String

    <DataMember()> _
    Public Property LastName() As String
        Get
            Return LastNameValue
        End Get

        Set(ByVal Value As String)
            LastNameValue = Value
        End Set
    End Property


    <DataMember(Name:="ID")> _
    Public IdNumber As Integer

    ' Note that you can apply the DataMemberAttribute to 
    ' a private field as well.
    <DataMember()> _
    Private Secret As String

    Public Sub New(ByVal newfName As String, ByVal newLName As String, ByVal newIdNumber As Integer)
        FirstName = newfName
        LastName = newLName
        IdNumber = newIdNumber
        Secret = newfName + newLName + newIdNumber.ToString()

    End Sub

    ' The ExtensionData field holds data from future versions 
    ' of the type.  This enables this type to be compatible with 
    ' future versions. The field is required to implement the 
    ' IExtensibleObjectData interface.
    Private extensionDataValue As ExtensionDataObject

    Public Property ExtensionData() As ExtensionDataObject _
       Implements IExtensibleDataObject.ExtensionData
        Get
            Return extensionDataValue
        End Get
        Set
            extensionDataValue = value
        End Set
    End Property
End Class

Public Class Test
    Public Shared Sub Main(ByVal args() As String)
        Try
            ReadObject("DataMemberAttributeExample.xml")
            WriteObject("DataMemberAttributeExample.xml")
        Catch exc As Exception
            Console.WriteLine("The serialization operation failed: {0} StackTrace: {1}", _
            exc.Message, exc.StackTrace)
        Finally
            Console.WriteLine("Press <Enter> to exit....")
            Console.ReadLine()
        End Try
    End Sub

    '<snippet1>
    Public Shared Sub ReadObject(ByVal filename As String)
        ' Create a new instance of the Person class.
        Dim p1 As New Person("Zighetti", "Barbara", 101)
        Dim writer As New FileStream(filename, FileMode.Create)
        Dim ser As New DataContractSerializer(GetType(Person))
        ser.WriteObject(writer, p1)
        writer.Close()
    End Sub
    '</snippet1>

    '<snippet2>
    Public Shared Sub WriteObject(ByVal filename As String)
        ' Deserialize an instance of the Person class 
        ' from an XML file.
        Dim fs As New FileStream(filename, FileMode.OpenOrCreate)
        Dim ser As New DataContractSerializer(getTYpe(Person))
        ' Deserialize the data and read it from the instance.
        Dim deserializedPerson As Person = ser.ReadObject(fs)
        fs.Close()
        Console.WriteLine(String.Format("{0} {1}, ID: {2}", _
        deserializedPerson.FirstName, deserializedPerson.LastName, deserializedPerson.IdNumber))
    End Sub
    '</snippet2>
End Class
'</snippet0>

'<snippet3>
<DataContract()> _
Public Class Employee
    ' The CLR default for as string is a null value.
    ' This will be written as <employeeName xsi:nil="true" />
    <DataMember()> _
    Public employeeName As String = Nothing

    ' This will be written as <employeeID>0</employeeID>
    <DataMember()> _
    Public employeeID As Integer = 0

    ' The next two will not be written because the EmitDefaultValue = false.
    <DataMember(EmitDefaultValue:=False)> Public position As String = Nothing
    <DataMember(EmitDefaultValue:=False)> Public salary As Integer = 0

    ' This will be written as <targetSalary>555</targetSalary> because 
    ' the 555 does not match the .NET default of 0.
    <DataMember(EmitDefaultValue:=False)> Public targetSalary As Integer = 555
End Class
'</snippet3>

Namespace Samples3
    '<snippet4>
    <DataContract()> _
    Public Class Employee
        <DataMember()> _
        Public employeeName As String = Nothing
        <DataMember()> _
        Public employeeID As Integer = 0
        <DataMember(EmitDefaultValue:=False)> _
        Public position As String = Nothing
        <DataMember(EmitDefaultValue:=False)> _
        Public salary As Integer = 0
        <DataMember(EmitDefaultValue:=False)> _
        Public Bonus As Integer = Bonus OrElse Nothing
        <DataMember(EmitDefaultValue:=False)> _
        Public targetSalary As Integer = 57800
    End Class
    '</snippet4>
End Namespace