CODEWITHSUNDEEP
dllvb6activex
nobitavn94
nobitavn94

Reputation: 327

VB6 debugging- doesn't go to error handling code

I'm maintaining a vb6 project(ActiveX DLL). When debugging, the app run into the following function:

Public Function HasValue(ByVal vValue) As Boolean

    On Error GoTo Err

    If IsMissing(vValue) Then
        HasValue = False
    ElseIf IsNull(vValue) Or Len(vValue) = 0 Then
        HasValue = False
    ElseIf isEmpty(vValue) Then
        HasValue = False
    Else
        HasValue = True
    End If

Exit Function

Err:

    If IsArray(vValue) Or IsObject(vValue) Then
        HasValue = True
    Else
        HasValue = False
    End If
End Function

and it stops at the line

ElseIf IsNull(vValue) Or Len(vValue) = 0 Then

vValue is a custom object, contains some properties(obviously, not null).

Although I didn't put any break point there, the app stopped there and alerted error dialog saying that "Run-time error '438': Object doesn't support this property or method".

We had error handling code but the app didn't run to error handling code. It just stopped at the line causing the error and I had to stop the application.

Do you have any idea about that? Thank you very much.

Upvotes: 2

Views: 1222

Answers (2)

k3b
k3b

Reputation: 14755

As far as i know vb6 does not support boolean short evaluation in

 ElseIf IsNull(vValue) Or Len(vValue) = 0 Then

so Len(vValue) = 0 is executed even if IsNull(vValue) is true.

changing your code to

...
ElseIf IsNull(vValue) Then
    HasValue = False
ElseIf Len(vValue) = 0 Then
    HasValue = False
ElseIf ...

might solve the problem

Upvotes: 0

Hiawatha Tiller
Hiawatha Tiller

Reputation: 156

As far as getting the popup running in the debugger, it is probably related to your "Error Trapping" settings in the IDE. Go To Tools->Options->General and see what selected under "Error Trapping". At first glance it seems odd that your error handler is testing the vValue in the event of an error. It makes more sense to me based on my limited understanding of this method to move both the IsArray and IsObject conditions up into the main testing logic. Just my 2 cents :)

Upvotes: 6

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