IndexOutOfRange Exception on foreach loop

Bill

I am getting a wierd result in my code sporadically. First of all, I am using an old VB .NET client dll which uses a Microsoft.VisualBasic.Collection, ugh! When I loop through the collection in my C# code, I occasionally get an exception.

the code ..
foreach (Tag tag in object.Tags)
{
...
}
sometimes I get an IndexOutOfRange, sometimes a NullReference, the code is invoked by a thread timer. Is it that the Collection isn't thread safe? It runs fine on my XP development machine, but not on the Windows Server 2003R2 server. I dont get it.

Any ideas?

2 Replies

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Bill18y ago
I did some research and found that the VisualBasic Collection object is not thread safe. So I changed my code to use the System.Timers.Timer object rather than the System.Threading.Timer object. It seems that things are running better since the timer will fire the TimerElapsed event then I can set the Enabled property at the end of the call. It is a bit slower, but accuracy is better and I would rather have accuracy than speed.
Scott Lysle18y ago
That is weird. Can you just wrap it up within a test to see that object.Tags is not null and has a count greater than zero.