Calculate the next value using VB code in SSRS report

Question

Hello community,
I require some help to calculate the next row value using VB if possible for the transaction posting date. This transaction posting from the next row will be used to populated the "To" column (minus -1 Date). I don't have access to the underlying sources to do a query using the LAG/Lead functions.

Problem:
I have a ssrs report where I would like to determine autonomously the "To" date. The "To" date is determined based on the next transaction posting date.
For example, I have a transaction posting date of 02-10-2021 and the subsequent transaction for this same entity on 05-03-2021. Therefore "To" date for this transaction should be 02-28-2021

Subsequently, the transaction posting date from 05-03-2021, the "To" date will depend on the next transaction posting date. If I have another transaction within the same month, for example occurring on 05-10-2021. Then the "To" date for the subsequent transaction will be 05-09-2021.

Here is original post I created for further information: https://learn.microsoft.com/en-us/answers/questions/994917/how-to-dynamic-calculate-the-to-date-based-on-the.html?childToView=997527#answer-997527

I am referencing a website where they added the Row field in the Query: https://stackoverflow.com/questions/39385975/get-previous-current-and-next-record-in-ssrs-report-in-a-page
I am not able to do this either.

Answer 1

1st table - will contain the set function in a textbox expression passing in the row number and value. This table can be hidden.

=setValue(RowNumber(Nothing),myfield.value)

2nd table - will contain the get function passing in the row number.

=getValue(RowNumber(Nothing)

Code Below

public dictLookup as new System.Collections.Generic.Dictionary(Of String, String)

Function setValue(value as object, value2 as object) as object

dictLookup.Add(value, value2)

return value

End Function

Function getValue(value as object) as object

If dictLookup.ContainsKey(value)

return dictLookup(value)

else

return value

end if

End Function