Public Class Class1
    Private v As Integer
    Shared Sub main()
        Dim c As New class1
        With c
            .v = 11
        End With
        Console.Write(c.v)
        Console.Read()
    End Sub

    Public Property pub_v() As Integer
        Get
            Return v
        End Get
        Set(ByVal value As Integer)
            v = value
        End Set
    End Property
End Class

Imports ClassLibrary1
Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, 
    ByVal e As System.EventArgs) Handles MyBase.Load
        Dim c As New Class1
        With c
            .pub_v = 11
        End With
        MsgBox(c.pub_v)
    End Sub
End Class

Public Class Class1
    Shared my_v As New second_class
    Shared Sub main()
        Dim c As New second_class
        c.v1 = 6
        Console.Write(c.v1) '6
        Console.Write(my_v.v1) '5
        Console.Write(second_class.v2) '0
        Console.Read()
    End Sub
End Class

Public Class second_class
    Public v1 As Integer
    Public Shared v2 As Integer
    Public Sub New()
        v1 = 5
    End Sub
End Class

Public Class Class1
    Inherits grand_father ' ถ้าตรงนี้เป็นพ่อจะให้ผลต่างออกไป
    Shared Sub main()
        Dim g As New grand_father
        Dim f As New father
        Console.Write(g.my_v()) ' 10
        Console.Write(f.my_v()) ' 11
        g_sub() '12
        Console.Read()
    End Sub
End Class

Public Class father
    Inherits grand_father
    Public Overloads Function my_v() As Integer
        Return 11
    End Function
End Class

Public Class grand_father
    Private v As Integer
    Public Function my_v() As Integer
        v = 10
        Return v
    End Function
    Shared Sub g_sub()
        Console.Write(12)
    End Sub
End Class

Imports ClassLibrary1 ' add reference required
Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        Dim g As New grand_father
        Dim f As New father
        MsgBox(g.my_v() & f.my_v()) ' 1011
        grand_father.g_sub() '12
    End Sub
End Class
+ winapp_call_grandfather.zip 96 KB 
(มี solution ของ windows forms application และ .dll 2 แฟ้ม คือ grand_father.dll + father.dll)
Root namespace: Classlibrary1 Project name: grand_father Solution name: grand_father Class name: grand_father
Root namespace: Classlibrary1 Project name: father Solution name: father Class name: father 

Public Class Mygrand
    Private g1 As Integer
    Public g2 As String
    Public Function cntg(ByVal x As String) As String
        g2 = CStr(Len(x))
        Return g2
    End Function
    Public Sub setg()
        exg1 = 1
        g2 = "two"
    End Sub
    Public Property exg1() As Integer
        Get
            If (g2 = "zero") Then Return 0 Else Return g1
        End Get
        Set(ByVal value As Integer)
            If (g2 = "two") Then g1 = 2 Else g1 = value
        End Set
    End Property
End Class
' mygrand.rar (source + .dll)

Public Class Myfather
    Inherits mygrand_ns.Mygrand
    Public Overloads Sub setg()
        exg1 = 3
    End Sub
End Class
' myfather.rar (source + .dll)

' add reference mygrand_as & myfather_as
Module mychild
    Sub Main()
        Dim nation As New mygrand_ns.Mygrand
        nation.exg1 = 7
        Console.Write(nation.exg1) ' 7
        Dim burin As New in_mychild
        burin.setg()
        Console.Write(burin.exg1) ' 3
        burin.g2 = "zero"
        burin.exg1 = 4
        Console.Write(burin.exg1) ' 0
        Console.Write(burin.cntg("two")) ' 2
        Console.Read()
    End Sub
End Module
Class in_mychild
    Inherits myfather_ns.Myfather
    Public Overloads Function cntg(ByVal x As String) As String
        Dim o As String = ""
        If (x = "one") Then o = "1"
        If (x = "two") Then o = "2"
        Return o
    End Function
End Class
' mychild.rar (source + .exe)

Public Class Form1
    Private Sub Form1_Load(ByVal sender As System.Object, 
    ByVal e As System.EventArgs) Handles MyBase.Load
        Dim myform As New in_form
        MsgBox(myform.cntg("three"))
    End Sub
End Class
Class in_form
    Inherits myfather_ns.Myfather
    Public Overloads Function cntg(ByVal x As String) As String
        Dim o As String = ""
        If (x = "one") Then o = "1"
        If (x = "two") Then o = "2"
        If (x = "three") Then o = "3"
        Return o
    End Function
End Class

Module Module1
    Sub Main()
        Dim chk As New checkid55
        chk.set_pass_admin("nation")
        chk.ex_id = 5401001
        Console.Write(chk.ex_id)  ' 5401001
        Console.ReadLine()
    End Sub
End Module

Public Class checkid54
    Private id As Integer
    Public admin_password As String
    Public Overridable Function check_admin() As Boolean
        If (admin_password = "pass") Then Return True Else Return False
    End Function
    Public Sub set_pass_admin(ByVal pass As String)
        admin_password = pass
    End Sub
    Public Property ex_id() As Integer
        Get
            If (check_admin()) Then Return id Else Return 0
        End Get
        Set(ByVal get_id As Integer)
            If (check_admin()) Then
                Dim id12 As Integer = CInt(Mid(CStr(get_id), 1, 2))
                If (Len(CStr(get_id)) = 7) Then
                    If (id12 >= 47 And id12 <= 54) Then
                        id = get_id
                    Else
                        id = 5400000
                    End If
                Else
                    id = 5499999
                End If
            End If
        End Set
    End Property
End Class

Public Class checkid55
    Inherits checkid54
    Public Overrides Function check_admin() As Boolean
        If (admin_password = "nation") Then Return True Else Return False
    End Function
End Class

Module Module1
    Sub Main()
        Dim w1 As New work3
        Console.Write(w1.x1 + w1.f1() + w1.f2())
        Console.Read()
    End Sub
End Module

Class work3
    Inherits work2
    Public Overrides Function f1() As Integer
        Return 3
    End Function
    Public Overrides Function f2() As Integer
        Return 2
    End Function
    Public Overloads Function f3() As Integer
        Return 4
    End Function
End Class

MustInherit Class work2
    Inherits work1
    Public x1 As Integer = 4 ' dim = private
End Class

MustInherit Class work1
    Public MustOverride Function f1() As Integer
    Public Overridable Function f2() As Integer
        Return 1
    End Function
    Public Function f3() As Integer
        Return 2
    End Function
End Class

Module Module1
    Sub Main()
        Dim child As New father
        child.getnum(100, "sombat", "panu")
        child.getnum(100, "sombat")
        child.getnum(100)
        Console.ReadLine()
    End Sub
End Module
Class father
    Inherits grand_father
    Overloads Sub getnum(ByVal num As Integer, ByVal name As String, ByVal lastname As String)
        Console.WriteLine(name & " " & lastname & " " & num)
    End Sub
    Overloads Sub getnum(ByVal num As Integer, ByVal name As String)
        Console.WriteLine(name & " " & " " & num)
    End Sub
    Overrides Sub getnum(ByVal num As Integer)
        Console.WriteLine("number is " & num)
    End Sub
End Class
Class grand_father
    Overridable Sub getnum(ByVal num As Integer)
        Console.Write(num)
    End Sub
End Class

Module Module1
    Sub Main()
        Dim g As New mycal55
        Dim name As String, surname As String
        name = Console.ReadLine()
        surname = Console.ReadLine()
        Console.WriteLine(g.getv(name, surname))
        Dim t As String
        t = Console.ReadLine()
        Dim var1 As Integer, var2 As Integer
        var1 = CInt(t.Split(" ")(0))
        var2 = CInt(t.Split(" ")(1))
        Console.WriteLine(g.getv(var1, var2))
        g.mycredit()
        Console.ReadLine()
    End Sub
End Module
Class mycal55
    Inherits mycal54
    Overloads Function getv(ByVal i1 As Integer, ByVal i2 As Integer)
        Return i1 + i2
    End Function
    Overrides Sub mycredit()
        Console.WriteLine("nation")
    End Sub
End Class
Class mycal54
    Function getv(ByVal s1 As String, ByVal s2 As String)
        Return s1 & " " & s2
    End Function
    Overridable Sub mycredit()
        Console.WriteLine("burin")
    End Sub
End Class

Module Module1
    Sub Main()
        Dim data As New work
        data.n = "แดง"
        data.s = "ทองดี"
        Console.WriteLine(data.ToString())
        Console.WriteLine(data.ToString("คุณ"))
        Console.ReadLine()
    End Sub
End Module
Class work
    Public n As String
    Public s As String
    Public Overrides Function ToString() As String
        Return "นาย " & n & " " & s
    End Function
    Public Overloads Function ToString(ByVal k As String) As String
        Return k & n & " " & s
    End Function
End Class

Module Module1
    Sub Main()
        Dim boy As New sale
        Console.WriteLine(boy.education("business administration"))
        Console.WriteLine(boy.talent("speach in public"))
        Console.WriteLine(boy.have_experience("NTU 5 years"))
        Dim girl As New clerk
        Console.WriteLine(girl.education("accounting"))
        Console.WriteLine(girl.talent("certification in ms word"))
        Console.WriteLine(girl.car_driving("yes"))
        Console.ReadLine()
    End Sub
End Module
Interface person
    Function education(ByVal t As String) As String
    Function talent(ByVal t As String) As String
End Interface
Class sale
    Implements person
    Function education(ByVal t As String) As String Implements person.education
        Return t
    End Function
    Function talent(ByVal t As String) As String Implements person.talent
        Return t
    End Function
    Function have_experience(ByVal t As String) As String
        Return t
    End Function
End Class
Class clerk
    Implements person
    Function education(ByVal t As String) As String 
Implements person.education
        Return t
    End Function
    Function talent(ByVal t As String) As String Implements 
person.talent
        Return t
    End Function
    Function car_driving(ByVal t As String) As String
        Return t
    End Function
End Class

Public Class Class1
    Public Shared Sub main()
        Dim c As New Class1, x As Integer = 5, y As Integer = 6
        c.swapi(x, y)
        Console.Write(x & y) ' 65
        c.swapint(x, y)
        Console.Write(x & y) ' 56
        Dim a As String = "A", b As String = "B"
        c.swapint(a, b)
        Console.Write(a & b) ' BA
        Console.Read()
    End Sub
    Sub swapi(ByRef x As Integer, ByRef y As Integer)
        Dim z As Integer = x
        x = y : y = z
    End Sub
    Sub swapint(Of any_type)(ByRef x As any_type, ByRef y As any_type)
        Dim z As any_type = x
        x = y : y = z
    End Sub
End Class

' add reference C:\Program Files\MySQL\MySQL Connector Net 6.5.4\Assemblies\v4.0\MySql.Data.dll
' in xampp (99 MB), start mysql

1. ติดตั้ง xampp เพื่อเปิดบริการ mysql ได้พอร์ท 3306
2. ติดตั้ง MySQL Connector Net 6.5.4 เพื่อเชื่อมต่อกับ MySQL
3. add reference mysql.data.dll
C:\Program Files\MySQL\MySQL Connector Net 6.5.4
\Assemblies\v4.0\MySql.Data.dll
4. มีระบบฐานข้อมูล mysql ซึ่งมีข้อมูลพร้อมทดสอบ ได้แก่
db:mysql,tb:time_zone_name,fld:time_zone_id,name

5. ตัวอย่าง console application ที่ประมวลผลแบบ sub main ใต้ class
Imports MySql.Data.MySqlClient
Public Class selectone
    Private Shared conn As New MySqlConnection
    Private Shared cmd As New MySqlCommand
    Private Shared opt As String
    Public Shared Sub main()
        Console.WriteLine(select_zone(1000000))
        Console.WriteLine(select_zone(101))
        Console.WriteLine(select_zone(102))
        Console.Read()
    End Sub
    Public Shared Function select_zone(ByVal zid As Integer) As String
        Dim zname As String = "not found"
        Dim connstring As String = "server=127.0.0.1;user id=root;password=;"
        connstring &= "database=mysql;charset=tis620;"
        conn.ConnectionString = connstring
        cmd.Connection = conn
        conn.Open()
        cmd.CommandText = "select time_zone_id,name from time_zone_name "
        cmd.CommandText &= "where time_zone_id = " & zid
        Dim r As MySqlDataReader = cmd.ExecuteReader()
        If r.Read() Then zname = r(1)
        conn.Close()
        Return zname
    End Function
End Class

6. ตัวอย่าง console application ที่ประมวลผลแบบ sub main ใต้ module
ซึ่งแบบนี้ไม่ต้องกำหนดฟังก์ชันแบบ shared
Imports MySql.Data.MySqlClient
Module module1
    Sub main()
        Dim s As New selectone
        Console.WriteLine(s.select_zone(1000000))
        Console.WriteLine(s.select_zone(101))
        Console.WriteLine(s.select_zone(102))
        Console.Read()
    End Sub
End Module
Public Class selectone
    Private conn As New MySqlConnection
    Private cmd As New MySqlCommand
    Private opt As String
    Public Function select_zone(ByVal zid As Integer) As String
        Dim zname As String = "not found"
        Dim connstring As String = "server=127.0.0.1;user id=root;password=;"
        connstring &= "database=mysql;charset=tis620;"
        conn.ConnectionString = connstring
        cmd.Connection = conn
        conn.Open()
        cmd.CommandText = "select time_zone_id,name from time_zone_name "
        cmd.CommandText &= "where time_zone_id = " & zid
        Dim r As MySqlDataReader = cmd.ExecuteReader()
        If r.Read() Then zname = r(1)
        conn.Close()
        Return zname
    End Function
End Class

7. เปลี่ยน class ที่พัฒนาไปเป็นแบบ class library จะได้แฟ้ม selectone_as.dll
+ selectone_as.dll 12 KB

8. ตัวอย่าง console application แบบเรียกใช้จาก class library
จะต้อง add reference mysql.data.dll และ selectone_as.dll
Imports selectone_ns
Module Module1
    Sub Main()
        Dim s As New selectone
        Console.WriteLine(s.select_zone(1000000))
        Console.WriteLine(s.select_zone(101))
        Console.WriteLine(s.select_zone(102))
        Console.Read()
    End Sub
End Module

9. การทำงานกับ windows forms application
จะต้อง add reference mysql.data.dll และ selectone_as.dll
Imports selectone_ns
Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object,
 ByVal e As System.EventArgs) Handles Button1.Click
        Dim s As New selectone
        TextBox1.Text = s.select_zone(102)
    End Sub
End Class

' add reference C:\Program Files\MySQL\MySQL Connector Net 6.5.4\Assemblies\v4.0\MySql.Data.dll
' in xampp (99 MB), start mysql
Imports MySql.Data.MySqlClient
Public Class Class1
    Public Shared Sub main()
        Dim conn As New MySqlConnection
        conn.ConnectionString = "server=127.0.0.1;user id=root;password=;database=mysql"
        Dim cmd As New MySqlCommand
        cmd.Connection = conn
        cmd.CommandText = "select name,time_zone_id from time_zone_name"
        Dim s As String = ""
        conn.Open()
        Dim r As MySqlDataReader = cmd.ExecuteReader()
        While r.Read()
            s &= r(0) & r(1) & Chr(10) ' 685 records
            ' If r("time_zone_id") = 3 Then Exit While
        End While
        conn.Close()
        Console.Write(s)
        Console.Read()
    End Sub
End Class

' add reference C:\Program Files\MySQL\MySQL Connector Net 6.5.4\Assemblies\v4.0\MySql.Data.dll
' in xampp, start mysql
Imports MySql.Data.MySqlClient
Public Class Class1
    Private Shared conn As New MySqlConnection
    Private Shared cmd As New MySqlCommand
    Private Shared opt As String
    Public Shared Sub main()
        conn.ConnectionString = "server=127.0.0.1;user id=root;password=;database=mysql;charset=tis620;"
        cmd.Connection = conn
        Console.WriteLine("sa,s,i,d,u of time_zone_id,name in time_zone_name")
        opt = Console.ReadLine()
        conn.Open()
        If opt = "s" Or opt = "sa" Then select_zone()
        If opt = "i" Then insert_zone()
        If opt = "d" Then delete_zone()
        If opt = "u" Then update_zone()
        conn.Close()
        Console.Read()
    End Sub
    Public Shared Sub select_zone()
        cmd.CommandText = "select time_zone_id,name from time_zone_name"
        Dim r As MySqlDataReader = cmd.ExecuteReader()
        Dim i As Integer = 1
        While r.Read()
            Console.WriteLine(r(0) & r(1)) ' 1684 records
            i = i + 1
            If i > 100 And opt <> "sa" Then
                Console.ReadLine()
                i = 1
            End If
        End While
    End Sub
    Public Shared Sub insert_zone()
        Dim zid As String = Console.ReadLine()
        Dim zname As String = Console.ReadLine()
        cmd.CommandText = "insert into time_zone_name (time_zone_id,name)values(" & zid & ",'" & zname & "')"
        Dim r As Integer = cmd.ExecuteNonQuery()
    End Sub
    Public Shared Sub delete_zone()
        Dim zid As String = Console.ReadLine()
        Dim zname As String = Console.ReadLine()
        cmd.CommandText = "delete from time_zone_name where time_zone_id = " & zid
        Dim r As Integer = cmd.ExecuteNonQuery()
    End Sub
    Public Shared Sub update_zone()
        Dim zid As String = Console.ReadLine()
        Dim zname As String = Console.ReadLine()
        cmd.CommandText = "update time_zone_name set name = '" & zname & "' where time_zone_id = " & zid
        Dim r As Integer = cmd.ExecuteNonQuery()
    End Sub
End Class

Imports MySql.Data.MySqlClient
Public Class Class1
    Private Shared conn As New MySqlConnection
    Private Shared cmd As New MySqlCommand
    Private Shared opt As String
    Public Shared Sub main()
        Console.WriteLine("s,i,d,u of time_zone_id,name in time_zone_name")
        opt = Console.ReadLine()
        Dim zid As String
        Dim zname As String
        If opt = "s" Then
            Dim l1 As Integer = Console.ReadLine()
            Dim l2 As Integer = Console.ReadLine()
            Console.Write(select_zone(l1, l2))
        End If
        If opt = "i" Then
            zid = Console.ReadLine()
            zname = Console.ReadLine()
            insert_zone(zid, zname)
            Console.Write(select_zone(1680, 1750))
        End If
        If opt = "d" Then
            zid = Console.ReadLine()
            delete_zone(zid)
            Console.Write(select_zone(1680, 1750))
        End If
        If opt = "u" Then
            zid = Console.ReadLine()
            zname = Console.ReadLine()
            update_zone(zid, zname)
            Console.Write(select_zone(1680, 1750))
        End If
        Console.Read()
    End Sub
    Public Shared Sub open_conn()
        If Len(conn.ConnectionString.ToString) = 0 Then
            conn.ConnectionString = "server=127.0.0.1;user id=root;password=;database=mysql;charset=tis620;"
        End If
        cmd.Connection = conn
        conn.Open()
    End Sub
    Public Shared Function select_zone(ByVal l1 As Integer, ByVal l2 As Integer) As String
        open_conn()
        cmd.CommandText = "select name,time_zone_id from time_zone_name limit " & (l1 - 1) & "," & (l2 - 1)
        Dim r As MySqlDataReader = cmd.ExecuteReader()
        Dim s As String = ""
        While r.Read()
            s &= r(0) & r(1) & Chr(10) ' 1684 records
        End While
        conn.Close()
        Return s
    End Function
    Public Shared Sub insert_zone(ByVal zid As String, ByVal zname As String)
        open_conn()
        cmd.CommandText = "insert into time_zone_name (time_zone_id,name)values(" & zid & ",'" & zname & "')"
        Dim r As Integer = cmd.ExecuteNonQuery()
        conn.Close()
    End Sub
    Public Shared Sub delete_zone(ByVal zid As String)
        open_conn()
        cmd.CommandText = "delete from time_zone_name where time_zone_id = " & zid
        Dim r As Integer = cmd.ExecuteNonQuery()
        conn.Close()
    End Sub
    Public Shared Sub update_zone(ByVal zid As String, ByVal zname As String)
        open_conn()
        cmd.CommandText = "update time_zone_name set name = '" & zname & "' where time_zone_id = " & zid
        Dim r As Integer = cmd.ExecuteNonQuery()
        conn.Close()
    End Sub
End Class
+ mysql_sidu2.zip

Imports ClassLibrary1.Class1
Public Class Form1
    Private Sub Button1_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button1.Click
        TextBox5.Text = ClassLibrary1.Class1.select_zone(TextBox3.Text, TextBox4.Text)
        TextBox5.Refresh()
    End Sub
    Private Sub Form1_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load
        TextBox1.Text = 1700
        TextBox2.Text = "ดวงดาว"
        TextBox3.Text = 1670
        TextBox4.Text = 1750
    End Sub
    Private Sub Button2_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button2.Click
        ClassLibrary1.Class1.insert_zone(TextBox1.Text, TextBox2.Text)
        TextBox5.Refresh()
    End Sub
    Private Sub Button3_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button3.Click
        ClassLibrary1.Class1.delete_zone(TextBox1.Text)
        TextBox5.Refresh()
    End Sub
    Private Sub Button4_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles Button4.Click
        ClassLibrary1.Class1.update_zone(TextBox1.Text, TextBox2.Text)
        TextBox5.Refresh()
    End Sub
End Class
+ mysql_form2.zip

Imports System.IO
Module Module1
 Dim p = New Process
 Sub Main()
  Dim mypro As Integer
  Console.Write("option: ")
  mypro = Console.ReadLine
  Select Case mypro
   Case 1
    Shell("c:\windows\notepad.exe", AppWinStyle.NormalFocus)
    Shell("explorer.exe http://www.google.com", AppWinStyle.NormalFocus)
   Case 2
    Dim pid1 As Integer 
    pid1 = Shell("c:\windows\notepad.exe", AppWinStyle.NormalFocus)
    Console.Write(pid1)
    Console.ReadLine()
    Shell("c:\windows\system32\taskkill.exe /pid " & pid1)
   Case 3
    start_process("C:\Windows\System32\Notepad.exe")
    Console.Write("start in process")
    Console.ReadLine()
    Try
     p.kill()
    Catch ex As Exception
     Console.Write(ex)
     Console.ReadLine()
    End Try
   Case 4
    Dim data(0) As Byte
    Dim fw As FileStream
    fw = New FileStream("c:\x.bat", FileMode.Create, FileAccess.Write)
    Dim cmd As String = "ipconfig"
    ReDim data(cmd.Length)
    For i = 0 To cmd.Length - 1: data(i) = Asc((cmd.Substring(i, 1))) :Next
    fw.Write(data, 0, cmd.Length)
    '
    cmd = Chr(13) + Chr(10)
    ReDim data(cmd.Length)
    For i = 0 To cmd.Length - 1: data(i) = Asc((cmd.Substring(i, 1))) :Next
    fw.Write(data, 0, cmd.Length)
    '
    cmd = "ping www.google.com > y.txt"
    ReDim data(cmd.Length)
    For i = 0 To cmd.Length - 1 : data(i) = Asc((cmd.Substring(i, 1))) : Next
    fw.Write(data, 0, cmd.Length)
    '
    cmd = Chr(13) + Chr(10)
    ReDim data(cmd.Length)
    data = System.Text.Encoding.UTF8.GetBytes(cmd)
    fw.Write(data, 0, cmd.Length)
    '
    cmd = "pause | type y.txt"
    data = System.Text.Encoding.UTF8.GetBytes(cmd)
    fw.Write(data, 0, cmd.Length)
    '
    fw.Close()
    Shell("c:\x.bat")
  End Select
 End Sub
 Sub start_process(ByVal c As String)
  p.StartInfo.FileName = c
  p.StartInfo.WindowStyle = ProcessWindowStyle.Normal
  p.Start()
 End Sub
End Module