Public Class AppData
        Public url As String = "[no url]"
        Public user As String = "[no user]"
        Public password As String = "[no password]"
    End Class

    Private configData As AppData
    Private _newConfig As Boolean
    Private file As String = "AppConfig.xml"
 
    Protected Overrides Sub OnLoad(ByVal e As System.EventArgs)
        ' Read the config data
        Dim nad As New AppData
        configData = AppDataManager.LoadClientConfig(nad, file)
        _newConfig = configData Is nad
 
        ' Set app values from config data
        TextBox1.Text = configData.url
        TextBox2.Text = configData.user
        TextBox3.Text = configData.password
    End Sub
 
    Protected Overrides Sub OnClosing(ByVal e As _
      System.ComponentModel.CancelEventArgs)
        ' Set new config data values
        configData.url = TextBox1.Text
        configData.user = TextBox2.Text
        configData.password = TextBox3.Text
 
        ' Write config data
        AppDataManager.SaveClientConfig(configData, file)
    End Sub

Imports System.Xml
Imports System.Xml.Serialization
 
Public Class AppDataManager
    ' Load/save App settings to local file
    Public Shared Function LoadClientConfig(ByVal initData As Object, ByVal _
      file As String) As Object
        Dim fs As FileStream
        Dim sr As StreamReader
 
        Try
            fs = New FileStream(file, FileMode.OpenOrCreate, FileAccess.Read)
            If fs.Length = 0 Then
                Return initData
            Else
                sr = New StreamReader(fs, System.Text.Encoding.UTF8)
                Dim xmlser As New XmlSerializer(initData.GetType())
                Return xmlser.Deserialize(sr)
            End If
        Catch ex As System.Exception
            MsgBox("Error in reading settings: " + ex.Message, _
              MsgBoxStyle.Exclamation, "Main")
            Return initData
        Finally
            If Not sr Is Nothing Then sr.Close()
            If Not fs Is Nothing Then fs.Close()
        End Try
 
    End Function
 
    Public Shared Function SaveClientConfig(ByVal data As Object, ByVal file As _
      String) As Boolean
 
        If data Is Nothing Then Exit Function
 
        Dim fs As FileStream
        Dim sw As StreamWriter
 
        Try
            fs = New FileStream(file, FileMode.Create, FileAccess.Write)
            sw = New StreamWriter(fs, System.Text.Encoding.UTF8)
 
            Dim xmlser As New XmlSerializer(data.GetType())
            xmlser.Serialize(sw, data)
 
        Catch ex As System.Exception
            MsgBox("Could not save settings: " + ex.Message, _
              MsgBoxStyle.Exclamation, "Main")
            Return False
        Finally
            If Not sw Is Nothing Then sw.Close()
            If Not fs Is Nothing Then fs.Close()
        End Try
 
        Return True
 
    End Function
 
End Class