VB.Net/Class/ReadOnly

Define and use Properties: ReadOnly

<source lang="vbnet"> Imports System Imports System.Collections

public class MainClass

  Shared Sub Main()
       Dim obj As New MyOwnClass("Firstobject")
       Dim x As Integer
       Console.WriteLine("This object is: " & obj.Name)
       Console.WriteLine("Other objects are: ")
       For x = 0 To MyOwnClass.OtherObjectCount - 1
           If x <> obj.MyIndex Then
               Console.WriteLine(obj(x).Name)
           End If
       Next
  End Sub

End Class

   Class MyOwnClass
       Implements IDisposable
       Private Shared myclasses As New ArrayList()
       Public Name As String
       Public Sub New(ByVal myname As String)
           MyBase.New()
           MyClasses.Add(Me)
           Name = myname
       End Sub
       Default Public ReadOnly Property OtherMyClassObjects(ByVal idx As Integer) As MyClass
           Get
               Return CType(MyClasses.Item(idx), MyClass)
           End Get
       End Property
       Public Shared ReadOnly Property OtherObjectCount() As Integer
           Get
               Return myclasses.Count
           End Get
       End Property
       Public ReadOnly Property MyIndex() As Integer
           Get
               Return myclasses.IndexOf(Me)
           End Get
       End Property
       Public Sub Dispose() Implements IDisposable.Dispose
           MyClasses.Remove(Me)
       End Sub
   End Class
          
      </source>

Define and use ReadOnly Class Property

<source lang="vbnet"> Imports System Imports System.IO

Public Class MainClass

 Shared Sub Main()
       Dim e As New Employee("Joe", 100000)
       Console.WriteLine(e.Name & "  has salary " & e.Salary)
       e.RaiseSalary(0.2D) "D necessary for decimal
       Console.WriteLine(e.Name & " still has salary " & e.Salary)
       Console.WriteLine()
       
 End Sub

End Class Public Class Employee

   Private m_Name As String
   Private m_Salary As Decimal
   Private Const LIMIT As Decimal = 0.1D
   Public Sub New(ByVal theName As String, ByVal curSalary As Decimal)
       m_Name = theName
       m_Salary = curSalary
   End Sub
   ReadOnly Property Name() As String
       Get
           Return m_Name
       End Get
   End Property
   ReadOnly Property Salary() As Decimal
       Get
           Return m_Salary
       End Get
   End Property
   Public Overloads Sub RaiseSalary(ByVal Percent As Decimal)
       If Percent > LIMIT Then
           "not allowed
           Console.WriteLine("Percent > LIMIT is not allowed")
       Else
           m_Salary = (1 + Percent) * m_Salary
       End If
   End Sub
   Public Overloads Sub RaiseSalary(ByVal Percent As Decimal, _
       ByVal Password As String)
       If Password = "special" Then
           m_Salary = (1 + Percent) * m_Salary
       End If
   End Sub

End Class

      </source>

Define ReadOnly Property

<source lang="vbnet"> Imports System Public Class MainClass

   Public Shared ReadOnly MaxEmployees As Integer = 100
   Shared Sub Main(ByVal args As String())
       Console.WriteLine(MaxEmployees)
   End Sub

End Class

      </source>

Demo Const and ReadOnly

<source lang="vbnet"> Imports System Public Class MainClass

   Shared Sub Main(ByVal args As String())
     Dim random As Random = New Random()
     Dim circle As CircleConstants = New CircleConstants(random.Next(1, 20))
     Dim radius As String = Convert.ToString(circle.RADIUS)
     Dim output As String = "Radius = " & radius & vbCrLf _
        & "Circumference = " + String.Format("{0:N3}", _
        circle.RADIUS * 2 * CircleConstants.PI)
     Console.WriteLine(output)
     
   End Sub

End Class " Encapsulate constants PI and radius. Class CircleConstants

  " PI is constant data member
  Public Const PI As Double = 3.14159
  " radius is uninitialized constant
  Public ReadOnly RADIUS As Integer
  " constructor of class CircleConstants
  Public Sub New(ByVal radiusValue As Integer)
     RADIUS = radiusValue
  End Sub " New

End Class " CircleConstants

      </source>