RandomAccess file for storing the custom objects : Structure Serialization « Class Module « VB.Net Tutorial

1. VB.Net Tutorial
2. Class Module
3. Structure Serialization

Imports System.IO

public class Test
   public Shared Sub Main
        Dim emp As New Employee

        Dim file_num As Integer = FreeFile()

        FileOpen(file_num, "MYFILE.DAT", OpenMode.Random, _
             OpenAccess.ReadWrite, OpenShare.Shared, _
             Len(emp))

        FilePut(file_num, New Employee(1, "A", "A"))
        FilePut(file_num, New Employee(2, "B", "B"))
        FilePut(file_num, New Employee(3, "C", "C"))

        Dim obj As ValueType = DirectCast(emp, ValueType)
        For Each i As Integer In New Integer() {3, 1,  2}
            FileGet(file_num, obj, i)
            emp = DirectCast(obj, Employee)
            Console.WriteLine(emp.ToString())
        Next i

        FileClose(file_num)
   End Sub
End class
    Public Structure Employee
        Public ID As Integer
        <VBFixedString(15)> Public FirstName As String
        <VBFixedString(15)> Public LastName As String

        Public Sub New(ByVal new_id As Integer, ByVal first_name As String, _
         ByVal last_name As String)
            ID = new_id
            FirstName = first_name
            LastName = last_name
        End Sub

        Public Overrides Function ToString() As String
            Return ID & ": " & FirstName & " " & LastName
        End Function
    End Structure

3: C               C
1: A               A
2: B               B