C# と VB.NET の質問掲示板

Public Class Class1

    Private _Value1 As String = ""
    Public Property Value1 As String
        Get
            Return Me._Value1
        End Get
        Set(value As String)
            Me._Value1 = value
            Call SaveClass1(Me) '値が変更された時ファイルに保存を行う
        End Set
    End Property

    Private _Value2 As String = ""
    Public Property Value2 As String
        Get
            Return Me._Value2
        End Get
        Set(value As String)
            Me._Value2 = value
            Call SaveClass1(Me) '値が変更された時ファイルに保存を行う
        End Set
    End Property

End Class

Module Module1
    Const fileName As String = "D:\class1.xml"

    'Class1をxmlファイルで保存
    Public Sub SaveClass1(ByRef cls As Class1)
        Try
            Dim serializer As New System.Xml.Serialization.XmlSerializer(GetType(Class1))
            Using sw As New System.IO.StreamWriter(fileName, False, New System.Text.UTF8Encoding(False))
                serializer.Serialize(sw, cls)
            End Using
        Catch ex As System.IO.IOException
            'xmlファイルを読込時発生するので無条件でスルー
        End Try
    End Sub

    'xmlファイルを読み込みClass1に展開
    Public Sub LoadClass1(ByRef cls As Class1)
        If System.IO.File.Exists(fileName) Then
            Dim serializer As New System.Xml.Serialization.XmlSerializer(GetType(Class1))
            Using sr As New System.IO.StreamReader(fileName, New System.Text.UTF8Encoding(False))
                cls = DirectCast(serializer.Deserialize(sr), Class1)
            End Using
        Else
            cls = New Class1
        End If
    End Sub

End Module

テスト用フォーム
Public Class Form1
    Private Sub Button1_Click(sender As Object, e As EventArgs) Handles Button2.Click
        'ストップウォッチを開始する 
        Dim sw As New System.Diagnostics.Stopwatch()
        sw.Start()

        Dim cls As Class1 = Nothing
        Call LoadClass1(cls)
        cls.Value1 = "test3"
        cls.Value2 = "test4"

        'ストップウォッチを止め結果を表示する 
        sw.Stop()
        Debug.Print("{0}", sw.Elapsed)
    End Sub
End Class