DataGrid on DataSet not displaying DataRow errors.

Question

Anyone come across this please? I created a multi-table dataset. I created a DataGrid and bound it to dataset with null string for tablename. That allows a datatable hierarchy to be viewed. I drill down and insert a new child record. I use the dataAdapter.Update command on a selection of DataRows that contains only the new DataRow. On return the DataRow does has a error and the HasErrors and RowError properties are set to True and the error message text. We do DataGrid.Refresh and try to view the row errors through the DataGrid. The row is still there, but no sign of the error. I thought DataGrid examined the row for you and would put a ! next to the row and would display the error message when the mouse rolled over the row?? Thanks!

p.jones · Answer

Strictly I used Microsoft's recommended DataTable.GetChanges(RowState) method to get the array of DataRows. This creates a new Datatable which is not inserted into the DataSet's collection of DataTables. The escalation of HasErrors by DataAdapter.Update() is set HasErrors on DataRow set HasErrors on DataTable use DataTable.DataSet property to set HasErrors on DataSet. Since the new DataTable is not part of the DataSet its DataSet property is Nothing so escalation to DataSet fails. The DataGrid with navigation set to DataSet and null DataTable looks for DataSet.HasErrors finds it is false and looks no farther hence the errors are not displayed. I proved this by Add(ing) the new DataTable to the DataSet's collection of DataTable's after giving it its own unique tablename. This then showed in DataGrid as a new table and navigation thereto showed the errors on the DataRow. If you navigate to the same DataRow via the original DataTable the DataGrid doesn't show the error. Solution was to use DataTable.Select(DataRowState) to get an array of DataRows and use that as the parameter to the overloaded DataAdapter.Update() method.