I'm using a virtual grid to displays some data. I've noticed however, that the grid requeries the data after the grid get painted. So if I pass another window accross the grid form, the values are requeried. Because my querycellinfo event can take a fairly large (relatively speaking) amount of time, this can make the grid repaint look very jerky. Is there any way for me to determine whether the cell has already been queried and prevent this requerying?
ADAdministrator Syncfusion Team February 24, 2003 06:14 PM
I looked into that and it is actually wrong that it gets requeried so often. There was a unnecessary direct call to QueryCellInfo instead of getting it from the volatile data cache.
We fixed that now. So, with the next patch that should be no issue any more.
SHSue HarrisFebruary 24, 2003 07:27 PM
> We fixed that now. So, with the next patch that should be no issue any more.
Excellent. Do you have any idea when the next patch will come out (few days/weeks/months)?
ADAdministrator Syncfusion Team February 25, 2003 02:19 AM
Days. It should be in the 5.2 release out in the next few days.
SFStephen FosterFebruary 27, 2003 08:38 PM
I notice that this occurs even when the mouse is moved over a cell (causing queryCellInfo to fire very very often. Is this corrected by this fix?
And, there are times where I've seen negative row/col values (usually -1). Is this expected?
Thanks in advance.
SHSue HarrisFebruary 27, 2003 09:48 PM
I've downloaded the new 1.5.2 Grid and I'm still getting the QueryCellInfo repeating when the control repaints. Did the fix not make it into the release?
ADAdministrator Syncfusion Team February 28, 2003 04:03 AM
Stephen - The row or col = -1 means that the style request is for a columnstyle (when row = -1 and col > -1) or for a rowstyle (when row >0 and col = -1).
QueryCellInfo (in version 1.5.2) will be hit once as your mouse enters the cell. It may also be hit again if garbage collection by the framework happens. But generally, you should count on the hit as it enters teh cell. This is different from teh earlier version where the QueryCellInfo was hit with each MouseMove even if you were in the same cell.
Sue - The change that made it into 1.5.2 is the one I described above, drastically reducing the QCI hits as you move the mouse. The problem you describe, repainting as you uncover teh grid, I am not sure there is a way to avoid this in general. Soppose teh external datasource has changed while the grid was covered. Hitting QCI lets the uncovered grid dynamically show these changes. Maybe Stefan will be able to handle this in some way, but it is a little tricky.
If your QCI code is time consuming, you might consider bufferring the time consuming data, and then just getting it from the buffer unless the buffer needs to be refreshed. I'll try to post a sample later in the next day or so.