Finding an error in a function in VB - vb.net

Question

I am trying to call a function in one class from another on a Timer.Elapsed. I can call test functions just fine, but when I call the actual function I want, I get no exceptions, but the function just doesn't run. I have tried adding in some error handling (Catch ex) and outputting frequent messages to a .txt file to see where it fails, but I am not getting any of these messages in my log when I know that the function I am using to write these messages to the log is working.
How can I find where my function contains an error if I have no access to error messages?
Adding my code below - this is my write to log function.
Public Shared Function Output_To_Log(ByVal message As String) As String
Dim strDate As String = Now.ToString("dd MMM yy HH:mm:ss ")
Dim strTodayDate As String = Now.ToString("yyyyMMMdd")
Dim file As New FileStream("C:\PHJones_Windows_Service\logs\Log" & strTodayDate & ".txt", FileMode.Append, FileAccess.Write)
Dim stream As New StreamWriter(file)
stream.WriteLine(message & " : " & strDate)
stream.Close()
Return ""
End Function
This is my Timer elapsed function.
Private Shared Sub Timer1_Elapsed(ByVal sender As System.Object, ByVal e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
Output_To_Log("Working")
PHJones.Start_Batch()
End Sub
This is my Start_Batch function, with references to my server blanked out with ****
Public Shared Function Start_Batch() As Integer
Try
Dim a As New running_check
a.check = 1
Dim files As String()
Dim File As String
Dim myProcess As New Diagnostics.Process()
Dim File_Name As String
Dim Running_FileName As String
RunTimer.Output_To_Log("Start_Batch starting")
Start:
RunTimer.Output_To_Log("Checking logs")
Dim log_check As Integer = check_logs()
RunTimer.Output_To_Log("Getting .DAT files.")
files = IO.Directory.GetFiles("****\phjones\to_phjones\", "*.DAT")
If files.Count > 0 Then
RunTimer.Output_To_Log("Counted " & files.Count & " files.")
Else
RunTimer.Output_To_Log("No files found.")
End If
For Each File In files
Try
RunTimer.Output_To_Log("Starting process for " & File)
Running_FileName = File & ".BAT"
RunTimer.Output_To_Log("Processing " & Running_FileName)
File_Name = File.Substring(26)
If System.IO.File.Exists("C:\PHJones_Windows_Service\Batch_Files\" & File_Name & ".BAT") Then
RunTimer.Output_To_Log("C:\PHJones_Windows_Service\Batch_Files\" & File_Name & ".BAT already exists")
Else
RunTimer.Output_To_Log("Copying " & Running_FileName & " to batch_files folder")
System.IO.File.Copy(Running_FileName, "C:\PHJones_Windows_Service\Batch_Files\" & File_Name & ".BAT", True)
End If
If (System.IO.File.Exists("C:\PHJones_Windows_Service\Batch_Files\" & File_Name & ".BAT")) Then
If (System.IO.File.Exists(Running_FileName)) Then
RunTimer.Output_To_Log("Deleting file " & Running_FileName)
System.IO.File.Delete(Running_FileName)
Else
RunTimer.Output_To_Log(File_Name & ".BAT does not exist in ****\phjones\to_phjones\processed")
End If
Else
RunTimer.Output_To_Log(File_Name & ".BAT failed to copy")
Throw New Exception(File_Name & ".BAT failed to copy to C:\PHJones_Windows_Service\Batch_Files")
End If
RunTimer.Output_To_Log("Executing batch file " & Running_FileName)
myProcess.StartInfo.UseShellExecute = True
myProcess.StartInfo.FileName = "C:\PHJones_Windows_Service\Batch_Files\" & File_Name & ".BAT"
myProcess.StartInfo.CreateNoWindow = False
myProcess.Start()
myProcess.WaitForExit()
If System.IO.File.Exists("****\phjones\to_phjones\" & File_Name) Then
RunTimer.Output_To_Log("****\phjones\to_phjones\" & File_Name & " already exists")
System.IO.File.Delete(File)
RunTimer.Output_To_Log(File & " has been deleted")
Else
RunTimer.Output_To_Log("Moving " & File)
System.IO.File.Move(File, "****\phjones\to_phjones\" & File_Name)
End If
Dim IWCnn = New OracleConnection(ConfigurationManager.ConnectionStrings("myConnectionString").ConnectionString)
Dim intRepair_Id As Integer = Mid(File_Name, 1, 7)
Dim intRepair_seq As Integer = Mid(File_Name, 8, 1)
RunTimer.Output_To_Log("Updating database for file " & File)
IWCnn.Open()
Dim StatusCmd As New OracleCommand("update works_orders " & _
"set wor_sco_code = 'ISS', wor_issued_datetime = sysdate" & _
" where wor_srq_no = " & intRepair_Id & _
" and wor_seqno = " & intRepair_seq, IWCnn)
StatusCmd.ExecuteNonQuery()
IWCnn.Close()
Catch ex As Exception
RunTimer.Timer1.Enabled = False
RunTimer.Output_To_Log("Exception thrown in PHJones 2010 - " & ex.Message)
Thread.Sleep(900000)
RunTimer.Timer1.Enabled = True
a.check = 0
Return 0
End Try
Next
a.check = 0
Catch ex As Exception
RunTimer.Output_To_Log("Exception thrown in PHJones 2010 - " & ex.Message)
End Try
Return 0
End Function
The entire RunTimer class.
Imports System.Configuration.ConfigurationSettings
Imports System.Data
Imports System.IO
Imports System.Diagnostics
Imports System
Imports System.Timers
Imports System.Threading
Imports System.ServiceProcess
Imports System.Configuration.Install
Public Class RunTimer
Inherits System.ServiceProcess.ServiceBase
Friend Shared WithEvents Timer1 As System.Timers.Timer
Public Counter As Integer = 0
Public Sub New()
MyBase.New()
InitializeComponents()
End Sub
Private Sub InitializeComponents()
Me.ServiceName = "RunTimer"
Me.AutoLog = True
Me.CanStop = True
Timer1 = New System.Timers.Timer()
Timer1.Interval = 15000
Timer1.Enabled = True
End Sub
' This method starts the service.
<MTAThread()> Shared Sub Main()
' To run more than one service you have to add them to the array
System.ServiceProcess.ServiceBase.Run(New System.ServiceProcess.ServiceBase() {New RunTimer})
End Sub
' Clean up any resources being used.
Protected Overloads Overrides Sub Dispose(ByVal disposing As Boolean)
MyBase.Dispose(disposing)
' TODO: Add cleanup code here (if required)
End Sub
Protected Overrides Sub OnStart(ByVal args() As String)
' TODO: Add start code here (if required) to start your service.
Timer1.Enabled = True
End Sub
Protected Overrides Sub OnStop()
' TODO: Add tear-down code here (if required) to stop your service.
Timer1.Enabled = False
Output_To_Log("Ended")
End Sub
Private Sub InitializeComponent()
Timer1 = New System.Timers.Timer
CType(Timer1, System.ComponentModel.ISupportInitialize).BeginInit()
Timer1.Enabled = True
CType(Timer1, System.ComponentModel.ISupportInitialize).EndInit()
End Sub
Private Shared Sub Timer1_Elapsed(ByVal sender As System.Object, ByVal e As System.Timers.ElapsedEventArgs) Handles Timer1.Elapsed
Output_To_Log("Working")
PHJones.Start_Batch()
End Sub

Answer 1

Since you're running as a service, you won't see ordinary error messages. It's possible there is an error between Output_To_Log("Working") in the Timer event and RunTimer.Output_To_Log("Start_Batch starting") of Start_Batch(). For example, if an error could occur in the initialization of Dim a As New running_check, or in the call itself, PHJones.Start_Batch(). Either of these would cause what you're seeing.