On error GoTo Question

[Les Stout]

Good day, i would just like to know if it is good practice to use "On
Error GoTo" within your code e.g.

Sub ChangeLcs()
' Open LCS list and modify
'
Application.WindowState = xlMinimized
Application.DisplayAlerts = False
'----- If there is no file goto NoFile MsgBox -----------
On Error GoTo NoFile
'----- If there is a file open it to process ------------ ChDir
"L:\LCS"
Workbooks.OpenText FileName:="L:\LCS\" & myLCS & ".xls",
Origin:=437, StartRow _
:=1, DataType:=xlDelimited, TextQualifier:=xlDoubleQuote, _
ConsecutiveDelimiter:=False, Tab:=True, Semicolon:=False,
Comma:=False _
, Space:=False, Other:=True, OtherChar:="|",
FieldInfo:=Array(Array(1, 1 _
), Array(2, 1), Array(3, 1), Array(4, 1), Array(5, 1), Array(6,
1), Array(7, 4), Array(8, 4), _
Array(9, 1), Array(10, 1)), TrailingMinusNumbers:=True
With Rows("1:1")
.Font.Bold = True
.HorizontalAlignment = xlCenter
.VerticalAlignment = xlBottom
.WrapText = False
.Orientation = 0
.AddIndent = False
.IndentLevel = 0
.ShrinkToFit = False
.ReadingOrder = xlContext
.MergeCells = False
End With
Columns("A:J").EntireColumn.AutoFit
Range("A2").Select
ShowFileAccessInfoLCS
'----- Message if there is no LCS file available --------NoFile:
MsgBox "Sorry, there is no LCS report for the project you selected
!"

End Sub


Les Stout

 

[NickHK]

Les,
There is nothing wrong with using error information; something it is best
(only) way to code.
However, it is only useful if you use it in someway. And include a "Exit
sub/Function" to avoid executing the handler, when no error has occurred
e.g.

On Error GoTo Handler

'...Code

Exit Sub
Handler:
Select Case Err.Number
Case 70
'Fix the problem
Resume
'Try that line again
Case 80
'Change something
Resume Next
'Continue on the next line
Case Else
'Cannot fix
Msgbox Err.Description
'Exit the sub
End Select
End Sub

The is also "On Error Resume Next", which is correctly can be useful, but
used wrongly will (probably) only lead to further errors being skipped over.

NickHK

 

[Les Stout]

Thanks very musch for the Explanation NickHk

Les Stout

 

[Carl Hartness]

To me, the helps are not clear when an On Error ceases to function, so
I usually include On Error GoTo 0 to cancel the handler before I leave
the procedure.

On Error GoTo Handler
... code ...
On Error GoTo 0
Exit Sub

Handler:
...code...
On Error GoTo 0
End Sub

Carl.

 

[Bob Flanagan]

Carl, the on error only stays in effect during a procedure. I like to have
an error handler always in effect, so I often do the following:

Sub Main_Procedure()
On error goto eTrap
X_Main_Procedure
exit sub
eTrap:
msgbox "Woops"
End Sub

The above will trap almost all errors. One big exception is errors in
userforms. For some reason those are not trapped by the above.

Bob Flanagan
Macro Systems
144 Dewberry Drive
Hockessin, Delaware, U.S. 19707

Phone: 302-234-9857, cell 302-584-1771
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