SSRS expression editor does not recognize embedded code function

Question

I have an SSRS report with information about invoices my company has issued with things like amount, date, payment, amount due, etc. I'm using SSRS 2008 (not R2) in Visual Studio 2008 environment. My issue has to do with formatting the report using the Expression editor. Currently, an invoice will be formatted as silver if the invoice has an Amount Due (a column) over 0.01 (outstanding invoice). We also issue credits (negative amounts) and these are almost always the negative amount of a previous invoice.

So, an invoice that has a credit issued to it will still show as silver because it's amount due > 0.01. But if there is a credit issued to this invoice, it's not actually outstanding and should be white. For example, if an invoice is $100.00, and there is a credit after for ($100.00), the original invoice's background color should be switched to white.

Here's where the code explanation comes in. I thought this was possible with custom VB code in the report, but it seems like the Expression editor in SSRS will not recognize my function as it says "Unrecognized identifier". I googled this a bit, and most of the topics I came across said that it will show that but actually work anyway. Well, I'm pretty sure it's not working at all, because I put this in as my expression and got all white cells for a certain column:

=IIF(Fields!Amount_Due.Value > 0.01, IIF(Code.HasCredit(Fields!Amount_Due.Value) = True, "Blue", "Silver"), "Red")

The HasCredit function is below.

Function HasCredit(ByVal currentAmt as Double) As Boolean

Dim i as Integer
Dim amt as Double
Dim amts as System.Collections.ArrayList = New System.Collections.ArrayList()
Dim negativeAmt as Double
Dim retValue as Boolean = "False"

i = 0

For i = 1 to Report.Parameters!Test.Count()
    amt = Report.Parameters!Test.Value(i)
    amts.Add(amt)
Next

negativeAmt = currentAmt * -1

If amts.Contains(negativeAmt) Then
    retValue = "True"
End If

Return retValue
End Function

When these two pieces are run, I get white background for all cells of this column. I read something on the net saying that only Shared functions would work, but I found multiple other examples showing functions that were not shared that worked. When I make it shared, it gives me: BC30369 Cannot refer to an instance member of a class from within a shared method or shared member initializer without an explicit instance of the class. due to the Report.Parameters!Test.Count() line. I got the idea for using Report.Parameters from http://social.msdn.microsoft.com/Forums/en-US/sqlreportingservices/thread/a7d59224-0ee5-491e-883b-2e5fcb3edeab.

So to reiterate, what I'm basically trying to do is get the values of each cell in this column into a collection and, for any two amounts where one amount has a negative equivalent, give it a white background instead of silver.

Answer 1

In SSRS 2008 R2, even if you reference a valid custom code method, the expression editor may still warn that the identifier is invalid. This does not always mean that it's invalid. My function worked even though that warning was thrown.