Scott is correct. However, horizontal scrolling is not optimized in the DG so it will never perform as well as vertical scrolling.
________________________________ From: flexcoders@yahoogroups.com [mailto:[EMAIL PROTECTED] On Behalf Of Scott Melby Sent: Friday, January 11, 2008 6:31 AM To: flexcoders@yahoogroups.com Subject: Re: [flexcoders] Dynamic DataGrid + slow horizontal scrolling Gary - Pretty much Every time I see datagrid performance issues it is due to 1 of the following 2 issues. 1) Heavy renderers (HBox VBox, etc,) - This is not the case for you application since you are just using the standard renderer. 2) Inefficient data source - I believe this is the case for your application. When you bind directly to e4x in an XMLListCollection your renderers (each column) have to re-parse that data from the e4x attribute each time they are called. The first thing I would suggest doing is creating an AS object that represents each row of your data. That object can have an attribute for each column (XML attr that you are displaying). In your dataHandler() method you can parse the e4x XML ONCE and construct a new AS object for each row, stick them in an ArrayCollection and bind your grid to that. The grid renderers will then be bound to pre-parsed data and will have to do a lot less work. This also happens to utilize memory much more efficiently (I believe e4x allocates a small chunk of memory on each parse). The e4x allocated memory does get cleaned up (I believe Alex said it does). But, it is not cheap to allocate tons of small chunks and clean them up repeatedly. hth Scott Scott Melby Founder, Fast Lane Software LLC http://www.fastlanesw.com <http://www.fastlanesw.com> Gary Smith wrote: Can anyone explain why this datagrid is so slow at horizontal scrolling: source and demo here: it takes a few seconds to start over the internet due to large number of columns being generated dynamically out from the xml source http://www.smithkjaer.dk/flex/TestComp.html <http://www.smithkjaer.dk/flex/TestComp.html> Note: If I disable the datagrids scrolling and scroll it in a canvas there is no performance problem when scrolling, except i miss my column header labels when vertical scrolling is used. -- View this message in context: http://www.nabble.com/Dynamic-DataGrid-%2B-slow-horizontal-scrolling-tp1 4731055p14731055.html <http://www.nabble.com/Dynamic-DataGrid-%2B-slow-horizontal-scrolling-tp 14731055p14731055.html> Sent from the FlexCoders mailing list archive at Nabble.com.
