VB.Net/Development/Err Number

Материал из VB Эксперт
Версия от 15:45, 26 мая 2010; Admin (обсуждение | вклад) (1 версия)
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Check Err.Number When there is an Error

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

   Shared Sub Main(ByVal args As String())
       Dim X As Integer
       " Try to calculate X.
       On Error Resume Next
       
       X = CalculateValue()
       
       Select Case Err.Number
           Case 0 " No error. Do nothing.
           Case 11 " Divide by zero. Set a default value.
               X = 1000
           Case Else " Unexpected error. Tell the user.
               Console.WriteLine("Error calculating X." & vbCrLf & Err.Description)
               Exit Sub
       End Select
       Console.WriteLine("X = " & X)
   End Sub
   
   Shared Private Function CalculateValue() As Integer
       Return 1 \ Integer.Parse("0")
   End Function

End Class

      </source>


On Error Resume Next

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

   Shared Sub Main(ByVal args As String())
       On Error Resume Next
       DoSomething()
       If Err.Number <> 0 Then
           Console.WriteLine("Error in DoSomething")
           Exit Sub
       End If
       DoSomethingElse()
       If Err.Number <> 0 Then
           Console.WriteLine("Error in DoSomethingElse")
           Exit Sub
       End If
   End Sub
   Shared Private Sub DoSomething()
           Throw New ArgumentException("Error in subroutine DoSomething")
   End Sub
   Shared Private Sub DoSomethingElse()
           Throw New ArgumentException("Error in subroutine DoSomethingElse")
   End Sub

End Class

      </source>