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    <p>I actually went through your code and hacked a bit to make it work on my devices. I can confirm your ListAdapter is just fine, and that the problem is elsewhere.</p> <p>This is what you do in the createDefaultLabelsList() method.</p> <pre><code>mItemsInList.clear(); ItemInRootList item; do { item = new ItemInRootList(); item.isLabel = true; item.id = c.getString(c.getColumnIndex(Labels.KEY_ID)); item.title = Labels.label(item.id); //TODO: fix this label.label = c.getString(c.getColumnIndex(Labels.KEY_LABEL)); item.unreadCount = c.getString(c.getColumnIndex(Labels.KEY_UNREAD_COUNT)); mItemsInList.add(item); } while (c.moveToNext()); </code></pre> <p>It seems that not using a local variable in your loop is the cause to your performance problem, believe it or not. Replace that with:</p> <pre><code>mItemsInList.clear(); do { ItemInRootList item = new ItemInRootList(); item.isLabel = true; item.id = c.getString(c.getColumnIndex(Labels.KEY_ID)); item.title = Labels.label(item.id); //TODO: fix this label.label = c.getString(c.getColumnIndex(Labels.KEY_LABEL)); item.unreadCount = c.getString(c.getColumnIndex(Labels.KEY_UNREAD_COUNT)); mItemsInList.add(item); } while (c.moveToNext()); </code></pre> <p>and enjoy your blazing fast list! This solved it for me on htc hero (2.1) and Xoom (3.1) using a ListActivity.</p> <p>That's how I would have done it in the first place - but I'm not exactly sure how this explains the sluggish behaviour with your original implementation.</p> <p>I found this out because in order to reproduce your issue I had to replace the way you built the list, just created a list of with 10k random labels and watched it scroll really fast. I then noticed we didn't use the exact same loop, you were adding the same reference over and over again while I was adding 10k different references. I switched to your implementation and reproduced the bug.</p>
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    1. POLots of garbage collection in a listview
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    1. USThomas Philipakis
    1. USThomas Philipakis
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    1. COThank you for your answer. I don't think that's the problem because the `List<>` is only created once. Moreover, the method you are referring to is not the one called usually. In fact the list can be built in two ways: default order, or using a `String` that gives the order of the items. The app uses the ordered one if possible, which is likely to be the case at all times. When I scroll, this code is not executed, so that is not the issue. Thank you very much tough, I appreciate the time you spent trying to help me.
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      1. USBenoit Duffez
    2. COit's worth a try, maybe? you're using basically the same idiom in your createOrderedLabelsList method. Try to create a new reference of Item inside the for loop and see how it goes? for (i = 0; i < nbItems; i++) { ItemInRootList item = new ItemInRootList(); ...
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      1. USThomas Philipakis
    3. CO...and sorry for the comment spam - I'm very new to Stackoverflow :) - the thing is I think the ListView goes much faster when its underlying Collection is storing Pointers (my version) rather than Instances (your version). Now that I think about it, it makes sense and might well explain all the garbarge collection that's happening on your side.
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