Define and Use your own Exception Class

Imports System

Public Class MainClass

    Shared Sub Main(ByVal args As String())
             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")

                 ' most derived exception type first
             Catch e As System.DivideByZeroException
                 Console.WriteLine( _
                    "DivideByZeroException! Msg: {0}", e.Message)
                 Console.WriteLine("HelpLink: {0}", e.HelpLink)

                 ' catch custom exception
             Catch e As MyCustomException
                 Console.WriteLine( _
                    "MyCustomException! Msg: {0}", e.Message)
                 Console.WriteLine("HelpLink: {0}", e.HelpLink)
             Catch ' catch any uncaught exceptions
                 Console.WriteLine("Unknown exception caught")
             Finally
                 Console.WriteLine("Close file here.")
             End Try
    End Sub
         ' do the division if legal
         Shared Public 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
                 ' create a custom exception instance
                 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

End Class

     Public Class MyCustomException
         Inherits System.ApplicationException

         Public Sub New(ByVal message As String)
             ' pass the message up to the base class
             MyBase.New(message)
         End Sub 'New

     End Class 'MyCustomException

Related examples in the same category

1.	Your own Exception Class
2.	A user-defined exception class
3.	Your own Object Expired Exception

Define and Use your own Exception Class : Exception Yours « Development « VB.Net

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