Selection in datagrid gets really slow

Question

I am importing data from file into arraylists. Then I use the arraylists to fill a DataTable that I use as a DataSource for a DataGrid. But when I refill the Grid with new data from files selection by pressing rowheader gets slower and slower. I get a delay before the entire row is highlighted. If I select a cell first then the rowheader for the row containing that cell the delay is not there. It only happens after refilling the table/grid a couple of times. It alså happens if I add columns to the table at run time (after adding about 5 columns it gets a noticable delay). What is up with that? -Atle

atlemann · Answer

I think the datagrid that shows the data from the datatable is the problem. For some reason it does not work to initialize the grid like this: DataTable dt = new DataTable(); DataGrid dg = new DataGrid() dg.DataSource = dt; By doing this I get lots of errors saying everything is out of bounds because my methods can't find any datacells. It works if I do it like this: DataTable dt = new DataTable(); DataGrid dg; dg.DataSource = dt. Now the datagrid never gets reset. That might be the problem. Even if I refresh it I get an error when trying to find the position of the top left cell of the grid for painting row headers. I really am out of ideas. -Atle

Andrzej Wegierski · Answer

May be: - use Clear() and AcceptChanges() before refilling to avoid having old data in datatable - try to reserve some memory for datatable with setting MinimumCapacity - recreate datatable instead of refill it