VB.Net Tutorial/Development/Debug

Convert Debug message to a file

<source lang="vbnet">Imports System.IO Imports System.Diagnostics Module Module1

   Sub Main()
       Dim Str As New FileStream("C:\DebugMessages.txt", System.IO.FileMode.Append)
       Dim DebugFile As New StreamWriter(Str)
       Dim Listener = New TextWriterTraceListener(DebugFile)
       Debug.Listeners.Add(Listener)
       Debug.AutoFlush = True
       Debug.WriteLine("")
       Debug.WriteLine("Messages generated at " & Now())
       Debug.WriteLine("In Button Click")
       Debug.WriteLine("Calling First")
       First()
       Debug.WriteLine("Exiting Button Click")
       Debug.Listeners.Remove(Listener)
       Str.Close()

   End Sub
   Private Sub First()
       Debug.WriteLine("In First")
       Debug.WriteLine("Calling Second")
       Second()
       Debug.WriteLine("Back in First")
   End Sub
   Private Sub Second()
       Debug.WriteLine("In Second")
   End Sub

End Module</source>

Debug Status

<source lang="vbnet">Imports System.Diagnostics Imports System.IO Module Module1

   Sub Main()
       Dim Str As FileStream
       Dim Listener As TextWriterTraceListener
       If (Debugger.IsAttached) Then
           Console.WriteLine("Debugging")
           Str = New FileStream("C:\DebugMessages.txt", System.IO.FileMode.Append)
           Dim DebugFile As New StreamWriter(Str)
           Listener = New TextWriterTraceListener(DebugFile)
           Debug.Listeners.Add(Listener)
           Debug.AutoFlush = True
       Else
           Console.WriteLine("Not debugging")
       End If

       Debug.WriteLine("")
       Debug.WriteLine("Messages generated at " & Now())
       Debug.WriteLine("In Button Click")
       Debug.WriteLine("Calling First")
       First()
       Debug.WriteLine("Exiting Button Click")
       If (Debugger.IsAttached) Then
           Debug.Listeners.Remove(Listener)
           Str.Close()
           Console.WriteLine("Done")
       End If
   
   End Sub
   Private Sub First()
       Debug.WriteLine("In First")
       Debug.WriteLine("Calling Second")
       Second()
       Debug.WriteLine("Back in First")
   End Sub
   Private Sub Second()
       Debug.WriteLine("In Second")
   End Sub

End Module</source>

Not debugging

Use Debug.Assert

<source lang="vbnet">Imports System.IO Module Module1

   Sub Main()
       Dim FileStr As StreamWriter
       System.Diagnostics.Debug.Assert(Not (FileStr Is Nothing), "FileStr is NULL")
       System.Diagnostics.Debug.Assert(Directory.Exists("\Temp"), "\Temp does not exist")
   End Sub

End Module</source>