Thanks for all the suggestions. I figured out the problem some days back and just posting the update here. I fixed the issue by firing a timer on each update and resetting the value when the timer gets triggered.

However, now I have to "flash" the cell based on "how" the value changed, i.e. if the value is numeric and it decreased I have to flash it with red, otherwise green. Any suggestions how to get the "previous" value in a cell just before initializeRow is fired?

Thanks for the response. I resolved the issue by keeping track of changes in the underlying data structure.

ok..i'm resurrecting another old post. sorry. not finding much on this topic. this post is the closest i found and was verified. (aside from Matts post which didn't quite meet  my requirements. a timer may work though).

i basically have a databound grid which receives new rows/updates in realtime (works great btw). but when a row is added/updated i want the row to flash an existing appearance object for like 2 seconds. but i don't want to lock up the gui if there are alot of updates. this may get into thread syncronization issues and i don't want to go that deep.

any help or tips would be apprecaited.

Al

Hi Al,

There's no built-in support for this. But you could probably achieve something pretty nice using a Timer. You would need to have some sort of construct to track which rows need the color and how long they have left to maintain that color and then on each tick of the timer, you just adjust the appearance of those rows based on the elapsed time.

Are you talking about doing this for individual cells or just entire rows? What kind of effect are you looking for? Blinking, fadeout, or just a solid color?

The biggest challenge I foresee you having with this is the performance. But with the appropriate optimizations, I can't see any reason why this can't be done.

thanks for responding Mike. not sure where to start. if using a ticker to declare it in the event everytime or declare globally. i would just change to a solid color for one second. like a blink i guess.

how long they have left to maintain that color....well i see it more as several rows blinking at practically the same time in wrong order. i might have to shelve this one for now.

Hi Al,

This seemed like such a fun and useful idea that I whipped up a quick sample.

I have attached my sample here. All you have to do is instantiate an instance of the GridCellColorizer class and pass in your grid. Then, when you want to color a cell temporarily, you call the AddCell method on the GridCellColorizer and pass in the cell, the color, and the time in milliseconds. The GridCellColorizer takes care of the rest.

You didn't answer my question about whether you wanted to do this on cells or rows, so I went with cells. Rows might be a bit trickier as you would have to apply the appearance to each cell within row.

I chose to use a DrawFilter, instead of setting the Appearance on the cell for a number of reasons. First off, this will be a lot more efficient, since cells that are scrolled out of view can be ignored. Second, I decided to use a sort've fade-out effect by drawing over the cell with a semi-transparent color which would have been impossible using an Appearance.

OK. i thought i was. i'm able to get the notifyprop changed event to fire when i directly set a value for one of the properties . i have to wire up to each property with a shared handler.

thanks for the help

Al Maiz said:

well i'm using notifypropertychanged for all the properties in my class and hoped to listen to those. but doesn't appear to be happening when bound to data source.

I'm not sure I follow you there. If you have your own custom class and implement this interface and you are setting properties and the interface notification is not firing, then something is wrong with your interface implementation. No? Unless something in your class is bypassing the property setter or changing the property values without firing the notification. This has nothing to do with the grid or data binding. 

Al Maiz said:

i tried to capture the gridAftercELL_update event but that wasn't firing for me when the cell was updated from the underlying data source.

Yes, that's correct.

ok. yes i have just the root band. well i'm using notifypropertychanged for all the properties in my class and hoped to listen to those. but doesn't appear to be happening when bound to data source. i tried to capture the gridAftercELL_update event but that wasn't firing for me when the cell was updated from the underlying data source. i guess it only works from modifiing the data directly (by hand/code)

i've turned your gridcellcolorizer into a gridrowcolorizer which appears to work though i'm still testing. It does use the listchanged event which is a bit silly, i need to determine update vs initial load time, etc. if coloring at a cellular level is to involved then i will pass. it's not worth the effort/risk i guess.

thanks

Hi Al,

Well, you are going to be limited by what your data source exposes. I think using the ListChanged interface is probably a good idea. The ListChanged notifications pass you an index, which is an index of the row that was changed in the data source. If your grid is filtered or sorted, finding the matching row in the grid might not be simple, though, especially if you are dealing with child rows

The grid's Rows collection has method called GetRowWithListIndex that will help. On the root band, this is straightforward. You can use the index you get from ListChanged to find the correct row. For a child row, you will have to find the parent row by it's ListIndex first, and then find the child row in the child rows collection.

I don't think ListChanged gives you which field was changed, though. So the only way to determine that would be to update whatever is changing the data so that it also sends you some kind of notification with more detailed info.

ideally , i want to pass the cell (RowXCol) that was updated in the datasource to the gridcellcolorizer, so the users see exactly which field just changed.