Create Custom Exception class : Custom Exception « Development « VB.Net Tutorial

1. VB.Net Tutorial
2. Development
3. Custom Exception

Option Strict On
 Imports System

 Public Class MyCustomException
     Inherits System.ApplicationException

     Public Sub New(ByVal message As String)
         MyBase.New(message)
     End Sub
 End Class

 Class Tester
     Public Shared Function DoDivide(ByVal a As Double, ByVal b As Double) As Double
         If b = 0 Then
             Dim e As New DivideByZeroException( )
             e.HelpLink = "http://www.java2s.com"
             Throw e
         End If
         If a = 0 Then
             Dim e As New _
               MyCustomException("Can't have zero divisor")
             e.HelpLink = "http://www.java2s.com"
             Throw e
         End If
         Return a / b
     End Function 'DoDivide

     Shared Sub Main( )
         Try
             Console.WriteLine("Open file here")
             Dim a As Double = 0
             Dim b As Double = 5
             Console.WriteLine("{0} / {1} = {2}", a, b, DoDivide(a, b))
             Console.WriteLine("This line may or may not print")

         Catch e As System.DivideByZeroException
             Console.WriteLine("DivideByZeroException! Msg: {0}", e.Message)
             Console.WriteLine("HelpLink: {0}", e.HelpLink)
         Catch e As MyCustomException
             Console.WriteLine("MyCustomException! Msg: {0}", e.Message)
             Console.WriteLine("HelpLink: {0}", e.HelpLink)
         Catch
             Console.WriteLine("Unknown exception caught")
         Finally
             Console.WriteLine("Close file here.")
         End Try
     End Sub
 End Class

Open file here
MyCustomException! Msg: Can't have zero divisor
HelpLink: http://www.java2s.com
Close file here.