by Timothy Vanover (2 Submissions)
Category: Debugging and Error Handling
Compatability: Visual Basic 3.0
Difficulty: Unknown Difficulty
Date Added: Wed 3rd February 2021
Rating: 
(2 Votes)
This is an example of how to use the intrinsic Visual basic App object to log errors to a file, which may later be helpful in debugging an application. The log file has the error number, error description, form name, sub or function name, and a date-time stamp when the error occurred. This also limits the error so that multiple loggings of the same error are not recorded in iterations.
Inputs
The public sub in the moderror.bas takes 4 parameters
LogErrors err.number, err.description, me.name , "MySubNameHere"
Assumes
The app.StartLogging will not work in the development enviroment. The code must be in a compiled executable for it to work.
Code Returns
This writes a .log file which may be opened with any text editor for examination as to the general area of an error that could crash your program.
API Declarations'* this code goes in a module for public use
'* Timothy A. Vanover
'* [email protected]
Public Sub LogErrors(lngErrNumber As Long, strErrDescription As String, _
strErrModule As String, strErrProcedure As String)
'*use to prevent recording multiple errors in loop
Static LastErrorRecorded As String
If CStr(Err.Number) & Err.Description & strErrModule & strErrProcedure = LastErrorRecorded Then
Exit Sub
Else
App.StartLogging App.Path & "\" & App.EXEName & ".log", vbLogToFile
App.LogEvent vbCrLf & _
"Error Description: " & strErrDescription & vbCrLf & _
"Error Number: " & lngErrNumber & vbCrLf & _
"Module Name: " & strErrModule & vbCrLf & _
"Procedure Name: " & strErrProcedure & vbCrLf & _
"Version Number: " & App.Major & "." & App.Minor & "." & App.Revision & vbCrLf & _
"Date: " & Format$(Now, "Short Date") & vbCrLf & _
"Time: " & Format$(Now, "Long Time") & _
vbCrLf & vbCrLf
LastErrorRecorded = CStr(Err.Number) & Err.Description & strErrModule & strErrProcedure
End If
End Sub
VBcoders'* This must be compiled into an executable for the intrinsic
'* error logging to work
'* It will not work from the development enviroment.
'* paste this code on to a form, save and compile it for the demo
Private Sub Form_Load()
'*here is an example of a sub which I raise errors in for the demo
ErrorDemoSub
MsgBox "Errors Recorded in Error Log File"
Unload Me
End Sub
Private Sub ErrorDemoSub()
Dim i As Integer
Dim ii As Integer
On Error GoTo MyErrorLog
'we'll simulate an error in a loop although we only log it one time
For i = 1 To 20
For ii = 1 To 5
Err.Raise i
Next ii
Next i
Exit Sub
MyErrorLog:
LogErrors Err.Number, Err.Description, Me.Name, "ErrorDemoSub"
Err.Clear
Resume Next
End Sub
