VB.Net Tutorial/Development/Predefined Exception

An overflow exception occurred

<source lang="vbnet">Module Module1

   Sub Main()
       Dim intItem1 As Integer = 0
       Dim intItem2 As Integer = 128
       Dim intResult As Integer
       Try
           intResult = intItem2 / intItem1
           Console.WriteLine("The answer is ", intResult)
           Console.WriteLine("Press Enter to continue...")
           Console.ReadLine()
       Catch
           Console.WriteLine("An overflow exception occurred.")
       End Try
   End Sub

End Module</source>

An overflow exception occurred.

Catch ApplicationException and ArgumentException

<source lang="vbnet">Option Strict On Public Module Tester

  Public Sub Main()
     Try
        RoutineA()
     Catch e As Exception
        Console.WriteLIne("Main error handler: " & e.Message)
     End Try
  End Sub
  Private Sub RoutineA()
     Try
        Throw New ApplicationException
     Catch e As ApplicationException
        Console.WriteLine("Exception in RoutineA: " & e.Message)
     End Try
     Try
        Throw New ArgumentException
     Catch e As ApplicationException
        Console.WriteLine("Exception in RoutineA: " & e.Message)
     End Try
     Console.WriteLine("About to exit RoutineA.")
  End Sub

End Module</source>

Exception in RoutineA: Error in the application.
Main error handler: Value does not fall within the expected range.

Catch EndOfStreamException

<source lang="vbnet">Imports System.IO public class Tester

  public Shared Sub Main
       Dim Stream As IO.StreamReader = IO.File.OpenText("test.txt")
       Try
           Console.WriteLine(Stream.ReadLine())
       Catch e As EndOfStreamException
           Console.WriteLine("EndOfStreamException")
       Catch e As IOException
           Console.WriteLine(e.Message)
       Finally
           Stream.Close()
       End Try
  End Sub
  

End class</source>

Catch FormatException

<source lang="vbnet">Public Class Tester

   Public Shared Sub Main
   
     Try
        Dim numerator As Integer = Convert.ToInt32("123")
        Dim denominator As Integer = Convert.ToInt32("321")
        Dim result As Integer = numerator \ denominator
        Console.WriteLine(result)
     Catch formattingException As FormatException
        Console.WriteLine("You must enter two integers")
     Catch dividingException As DivideByZeroException
        Console.WriteLine(dividingException.Message)
     End Try
   End Sub

End Class</source>

0

InvalidCastException

<source lang="vbnet">Option Strict On Public Module ThrowStatement

  Public Function GetEvenNumber() As Integer
     Dim inputString As String = "asdf"
     Throw New InvalidCastException("Unable to convert "" & inputString & "" to an integer")
     Return 0
  End Function

  Public Sub Main
        Try
           Console.WriteLine(GetEvenNumber())
        Catch e As InvalidCastException
           Console.WriteLine(e.GetType().Name & ": " & e.Message)
        Catch e As Exception
           Console.WriteLine(e.GetType().Name & ": " & e.Message)
        End Try
  End Sub

End Module</source>

InvalidCastException: Unable to convert "asdf" to an integer

System.Data.ConstraintException

<source lang="vbnet">Imports System.IO public class Tester

  public Shared Sub Main
       Dim y As Integer
       Dim x As Integer
       Dim z As Integer
       Try
           x = 1
           y = 0
           z = x / y
       Catch e As DivideByZeroException
           Console.WriteLine("You have attempted to divide by zero!")
           y = 2
           z = x / y
       Catch e As OverflowException
           Console.WriteLine("You have encountered an overflow exception. ")
           y = 2
           z = x / y
       Catch e As System.Data.ConstraintException
           Console.WriteLine("You have encountered a constraint exception. ")
           y = 2
           z = x / y
       Finally
           Console.WriteLine(x & "/" & y & " = " & z)
       End Try
  End Sub
  

End class</source>

You have encountered an overflow exception.
1/2 = 0

Throw ArgumentOutOfRangeException

<source lang="vbnet">Imports System.Drawing Imports System.Drawing.Drawing2D Public Class Tester

   Public Shared Sub Main
       Dim number As Decimal
       number = CDec(Val("123.123"))
       Console.WriteLine("Factorial(" & number & ")... ")
       Console.WriteLine(Factorial(number))
       
   End Sub
   Public Shared Function Factorial(ByVal number As Decimal) As Decimal
       Select Case number
           Case Is < 0
               Throw New ArgumentOutOfRangeException( _
                   "Negative numbers not allowed.")
           Case Is = 0
               Return 1
           Case Else
               Return number * Factorial(number - 1)
       End Select
   End Function

End Class</source>

Factorial(123.123)...
Unhandled Exception: System.ArgumentOutOfRangeException: Specified argument was out of the range of
valid values.
Parameter name: Negative numbers not allowed.
   at Tester.Factorial(Decimal number)

Throw ArithmeticException

<source lang="vbnet">Module Module1

   Sub Main()
           Try
               AddNumbers(1, 2)
           Catch Except As Exception
               Console.WriteLine("Call generated error: " & Except.Message)
           End Try
   End Sub
   Function AddNumbers(ByVal A As Integer, ByVal B As Integer) As Integer
       Try
           Throw New ArithmeticException()
       Catch Except As Exception
           Console.WriteLine(Except.Message)
       End Try
   End Function

End Module</source>

Overflow or underflow in the arithmetic operation.

Throw DivideByZeroException

<source lang="vbnet">Module Module1

   Sub Main()
           Try
               DoMod(1, 2)
           Catch Except As Exception
               Console.WriteLine("Call generated error: " & Except.Message)
           End Try
   End Sub
   Function DoMod(ByVal A As Integer, ByVal B As Integer) As Integer
       Try
           Throw New DivideByZeroException()
       Catch Except As Exception
           Console.WriteLine(Except.Message)
       End Try
   End Function

End Module</source>

Attempted to divide by zero.