I'm using VS2010, C#, .net3.5.
I have a problem when binding data to a combobox. Let's say i have two tables with a parent-child relation, T1 (child), and T2 (parent).
I have a combobox and textbox which bind to bindingsource B2. The combobox's selectedvalue binds to a FK column in T1. In the textbox i want to depict a column from T2, corresponding with FK in T1 = PK in T2. So i want to perform a lookup in another table.
Problems arise when the FK in T1 is NULL. To which row should B2 bind? Its 'Current' property stays on the previous row and is not updated because the selectedvalue is NULL. Setting the position of B2 to -1 does not seem to help. When i navigate back to the previous row, the Current property will not be updated, because it is already there.
Any suggestions would be appreciated..!