What's the deal with this Lambda?

Answer 1

The = operator pulls double duty for both assignment and equality in VB.Net. Is it possible it's being interpreted incorrectly as assignment here? Try this instead:

Dim count As Func(Of Integer, Boolean) = Function(x As Integer) Return x = 1

Answer 2

Your lambda function (checks whether ONE item is selected) and your stated goal (run message box if >1 items are selected) are not mutually exclusive. Neither covers the case when NO items are selected.

So if no items are selected, then "x=1" is false, so the "If" statement fails and you fall through to the message box.

What about writing

Dim count As Func(Of Integer, Boolean) = Function(x As Integer) (x <= 1)

??