Controls

[feurich]

Hi there everyone.

I'm trying to clear some contrlos created at runtime on a combobox Selectedvaluechange event but I get a strange error. could someone take a look at the code and maybe give me some info on what i'm doing wrong. This is test code i'm using, but it reacts the same in my org. code.

The error occurs when clearing the controls in the clearcontrols routine. The code comes across a control that is not defined and gives the error "Object reference not set to an instance of an object"

 

GreetZ,

 

Feurich

form1.vb

Edited November 3, 2003 by feurich

[PlausiblyDamp]

try changing the ClearControls sub to

   Private Sub ClearControls()
       '*** Clear controls But leave Combobox1 on the form.
       Dim i As Integer
       For i = Me.Controls.Count - 1 To 0 Step -1
           If Me.Controls(i).Name <> "ComboBox1" Then
               Me.Controls(i).Dispose()
           End If
       Next
   End Sub

[feurich]

EUREKA !!!!!

 

It works ...i'm baffled.

Could you please explain why the controls collection has to be looped backwords ???

 

THanks a mil.

 

Cire

[PlausiblyDamp]

If you are disposing of them while going forwards then I think the internal numbers are being moved down by one everytime you delete something. Starting at the top and working down prevents you skipping over them in this way.

[feurich]

Makes Sense

 

That makes sense.

I have read "everything" on Controls collection in the MSDN but this behaviour isn't mentioned anywhere.

That's why there are these forums.

 

GreetZ,

 

Cire:p