Question for loop won't remove all items from listbox or array

[evanz]

I have an array list declared globally as
Dim OnGraph as new ArrayList

[XCODE]On Error Resume Next

Dim tmp() As String, i As Integer, tmp2() As String, tmpid As String
tmp = Split(lstVials.SelectedItem, ":") 'it will obtain vial name "B366"
tmpid = tmp(1)
For i = 0 To OnGraph.Count
tmp2 = Split(OnGraph.Item(i).ToString, ":")
'This will also obtain "B366"
If tmp2(0) = tmpid Then
OnGraph.RemoveAt(i) 'even though the program hits this line of code it does not remove any items.
End If
Next i​

[/XCODE]

I also get these two debug errors

A first chance exception of type 'System.NullReferenceException' occurred in Greenlight.exe
A first chance exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll

I read something about enumeration but i couldnt find any good threads/articles on google.

Any tips?

 

[JohnH]

When removing from the collection you are looping through use a For-Next loop that goes from highest index to lowest by Step-1. For...Next Statement (Visual Basic)

 

[evanz]

That method didn't work either. When I load the arraylist there are 23 items. the for loop will remove them up until item 12 and then stops. Even though when debugging it hits the ongraph.removeat(i) line. When it hits item 12 it gives me this error

A first chance exception of type 'System.ArgumentOutOfRangeException' occurred in mscorlib.dll
{"Index was out of range. Must be non-negative and less than the size of the collection. Parameter name: index"}

 

[JohnH]

the for loop will remove them up until item 12 and then stops.

Not if you did what I said:

For i = (OnGraph.Count - 1) To 0 Step -1

 

[evanz]

ahh I had it switched around. It works perfectly thank you so much!