> > Interesting… I usually just create a new View every time in getView… so > I've never run into that. > That should be fine if you don't have a lot of items or if your views are kept very simple.... Otherwise doing this will cause choppiness when scrolling the listview.
Thanks, Justin Anderson MagouyaWare Developer http://sites.google.com/site/magouyaware On Sat, Jul 28, 2012 at 2:20 PM, soynerdito soynerdito <[email protected] > wrote: > A nice post describing that is here > http://lucasr.org/2012/04/05/performance-tips-for-androids-listview/ > With an example of what is called a view holder to have a performance > improvement. > Also in the Google IO 2010 it is well explain from the developer itself > http://www.youtube.com/watch?v=wDBM6wVEO70 > > > > On Sat, Jul 28, 2012 at 2:41 PM, bob <[email protected]> wrote: > >> Interesting… I usually just create a new View every time in getView… so >> I've never run into that. >> >> >> >> On Saturday, July 28, 2012 6:10:50 AM UTC-5, Sergio Panico wrote: >>> >>> Hi all, >>> I thank all for your answers. >>> >>> I've understood the "strange" behaviour that doesn't makes my ListView >>> to refreshes correctly. >>> >>> Here is the link where I've found the solution: >>> https://groups.google.com/**forum/?fromgroups#!topic/** >>> android-developers/2Ub4yhyKumM<https://groups.google.com/forum/?fromgroups#%21topic/android-developers/2Ub4yhyKumM> >>> >>> This topic clearly explains that, when the callback method "getView" is >>> called, the parameter "convertView" is null only when ListView tries to >>> draw the first 5 items, from "A" to "E". When I scroll down the content of >>> the list, and the ListView draws the items 6 and 7, it "reuses" the views >>> previoulsy created, hence "convertView" is not null and my getView >>> implementation goes into "else" branch. >>> >>> What I've missed was to bind the "old" view, with the "new" model item >>> getting showed. So the fix was simply to add, in this branch, the update of >>> the bind between "recycled" view and model item. >>> >>> HTH >>> Sergio >>> >>> >>> >>> Il giorno giovedì 26 luglio 2012 12:59:05 UTC+2, Sergio Panico ha >>> scritto: >>>> >>>> Hi all, >>>> I need your help to understand the refresh behaviour of a ListView >>>> where I've defined a my custom view for the ListView's items. >>>> >>>> I think It's better explain it with an example: >>>> my adapter contains 7 items: A, B, C, D, E, F, G correctly initialized, >>>> filled and working. The associated ListView shows 5 (out of 7) items: A, B, >>>> C, D, E. >>>> The problem is that, when I scroll down the ListView's content instead >>>> of showing me items F and G, I've got A and B items again. I understood >>>> that this is "only" a viewing issue becouse the model elements associated >>>> with the last two items, correctly belong to F and G items. :| >>>> >>>> Following the ovveride of getView(...) method of my adapter (extending >>>> BaseAdapter): >>>> >>>> @Override >>>> public View getView(int position, View convertView, ViewGroup >>>> parent) { >>>> MyItemView miv = (( MyItemView ) convertView); >>>> >>>> if (context == null) return null; >>>> >>>> if (convertView == null) { >>>> miv = new MyItemView (........); >>>> ..... >>>> } else { >>>> miv.refreshView(); //refresh the view content >>>> } >>>> >>>> return miv; >>>> } >>>> >>>> and the refreshView() method of MyItemView (extending LinearLayout): >>>> >>>> @Override >>>> public void refreshView() { >>>> label1.setText(......); >>>> label2.setText(......); >>>> label2.setText(......); >>>> >>>> invalidate(); >>>> } >>>> >>>> Thanks a lot to all! >>>> Bye >>>> Sergio >>>> >>> -- >> You received this message because you are subscribed to the Google >> Groups "Android Developers" group. >> To post to this group, send email to [email protected] >> To unsubscribe from this group, send email to >> [email protected] >> For more options, visit this group at >> http://groups.google.com/group/android-developers?hl=en >> > > -- > You received this message because you are subscribed to the Google > Groups "Android Developers" group. > To post to this group, send email to [email protected] > To unsubscribe from this group, send email to > [email protected] > For more options, visit this group at > http://groups.google.com/group/android-developers?hl=en > -- You received this message because you are subscribed to the Google Groups "Android Developers" group. To post to this group, send email to [email protected] To unsubscribe from this group, send email to [email protected] For more options, visit this group at http://groups.google.com/group/android-developers?hl=en
