Steps: Private Sub Data Grid View1_Cell Validating(By Val sender As System. Is In Edit Mode Then Dim c As Control = Data Grid View1. dim my Data Table as Data Table dim tmp Str as String dim s ID as Integer = 1 ... Get Data() ' Reads the data from MS-Access table ... Rows tmp Str = name Item("lastname") " " name Item("initials") If my Item("s ID")=s ID Then ' Do something End If ' print tmp Str Next Microsoft came up with DBNull in . However, it's a pain in the behind to use because you can't create a strongly-typed variable to store a genuine value or null. Just a suggestion, but what I normally do is this: While reader. Add(New DDLItem( _ CType(reader("rid"), Integer), _ CType(reader("Item_Status"), String), _ CType(reader("Text_Show"), String), _ CType( IIf(Is DBNull(reader("Text_Use")), "", reader("Text_Use")) , String), _ CType(reader("Text_System Only"), String), _ CType(reader("Parent_rid"), Integer))) End While VB. However, you are still stuck with large chunks of API that use DBNull, and they can't be changed.
In the Cell End Edit event handler, set the Error Text property on the row to the empty string.
When you bind to a data source that contains multiple lists or tables, set the Data Member property to a string that specifies the list or table to bind to.