I don't think it's a problem with llbl per se.

Here's the code:

        For Each Student As Student In gGlobalVars.GradeBookStudents
            For Each SubjectAreaTchr As SubjectAreaTchrStudEntity In Student.StudentEntity.SubjectAreaTchrStud
                If SubjectAreaTchr.SubAreaTchrIdent = -1 Then
                    Student.StudentEntity.SubjectAreaTchrStud.Remove(SubjectAreaTchr)
                End If
            Next
        Next

Here's the Error:

 ************** Exception Text **************
System.InvalidOperationException: Collection was modified; enumeration operation may not execute.
   at System.Collections.ArrayListEnumeratorSimple.MoveNext()
   at MedfordSchoolDistrict.ElementaryGradeBook.frmSubjectAreaTeacher.frmSubjectAreaTeacher_Closing(Object sender, CancelEventArgs e) in C:\Documents and Settings\dave.vorgang\My Documents\Visual Studio Projects\ElementaryTeachersDesktop\ElementaryGradeBook\frmSubjectAreaTeacher.vb:line 233

I'm guessing that it doesn't like me removing items while i'm running thru the collection.

So, how do I accomplish what I want to do?

Thanks,

Fishy

I think this will remove it:

        For Each Student As Student In gGlobalVars.GradeBookStudents
            For Each SubjectAreaTchr As SubjectAreaTchrStudEntity In Student.StudentEntity.SubjectAreaTchrStud
                If SubjectAreaTchr.SubAreaTchrIdent = -1 Then
                    SubjectAreaTchr = Nothing
                End If
            Next
        Next

Just setting it to Nothing instead of removing from collection.

You can't modify anything in a collection you're using in a foreach . You have to add the elements to remove to an arraylist, then foreach over that to remove it from the other collection.

if you are worried about performnace you can also use a for loop instead. When you hit an element you need to remove just decrement your counter by one.

Matt