主题：（求助）表间行复制代码修改

If e.DataCol.Name = "逻辑列名" AndAlso e.DataRow("逻辑列名") = True Then
     Dim dr As DataRow = DataTables("表B").AddNew
     For Each dc As DataCol In DataTables("表B").DataCols
         dr(dc.Name) = e.DataRow(dc.Name)
     Next
End If

如果表A重要字段为空，则不许复制，这段代码怎么改？