Specified cast is not valid in vb.net

Question

Getting this error when assigning an integer variable to a value coming back from a SQL stored procedure that may at times contain a NULL.

   System.InvalidCastException: Specified cast is not valid. 

Code snippet:

   Dim iUserId As Nullable(Of Integer)

  ' Get the UserId associated to the server.
  .CommandType = Data.CommandType.StoredProcedure
  .CommandText = "SelectUserIdByServerId"
  .Parameters.Clear()
  .Parameters.AddWithValue("@ServerId", Request("serverid"))

  ' Returns back 1 column.
  iUserId = .ExecuteScalar()

I though that if I have: Dim iUserId As Nullable(Of Integer), that it should not have a problem with it.

Answer 1

ExecuteScalar() returns Object which is an integer or DbNull value.
So you need to write it like this:

Dim tmp As Object = .ExecuteScalar()
iUserId = if(Convert.IsDbNull(tmp), new integer?(), directcast(tmp, integer))