Most efficient way to display 20K+ items in a listview?

load items

only option is show a message "loading...."

I may be wrong

Regards

Alex

as I said, "any idea welcome"! Thanks. Actually this is what I am doing at the moment. I have changed the text of the button that executes the query to "Searching..." during the creation of the list.

I had an idea that I will try next, is to use a scrollview and only load the first 500 results. Then I would use the scrollchanged event to measure if the scroll is close to the end of the list. If so, then I would load another 500 results. This method could be fast on the query side, but memorywise, I think it would be slow, and I can imagine some lag during the scroll.

jmon said:

hi,

I have this application with a big database, and sometimes I have queries resulting in more than 20000 results. At the moment I use the default listview with 2 lines and bitmap to display the result, but it can get slow on some devices (like 3 - 5 seconds to create the whole list).

My question is if there is a methods that could allow me to speed up this? I like to have results in less than a second. I tried scrollview, but I found it even slower.

Any idea is welcome!

jmon.

Click to expand...

UltimateListView.

I think ExecQueryAsync should be the answer you want. Just add Async to your existing query.

Informatix said:

UltimateListView.

Click to expand...

Thanks. Very impressive work. My application doesn't generate revenue, so I am a bit relluctant to pay the fee. But just for the fun of trying your library, I am starting to be interested.

demasi said:

I think ExecQueryAsync should be the answer you want. Just add Async to your existing query.

Click to expand...

Thanks a lot for your suggestion. I think that's exactly what I need. I'll post back after doing some tests.

Loading 20000 bitmaps will be slow. First make sure that you use LoadBitmapSample or you will quickly run out of memory.

Showing a list with 20000 items is in many cases a design issue. Is it sorted in some way? Do you expect the user to go over all the list?

You can use CustomListView class and add new items whenever the user scrolls to the bottom.

Erel said:

Loading 20000 bitmaps will be slow. First make sure that you use LoadBitmapSample or you will quickly run out of memory.

Showing a list with 20000 items is in many cases a design issue. Is it sorted in some way? Do you expect the user to go over all the list?

You can use CustomListView class and add new items whenever the user scrolls to the bottom.

Click to expand...

Yes, the user might want to scroll quickly through the list. The list is sorted, and it is possible to filter the list too. In most cases I would say that once the user has set the filters, he will end up with a list with a maximum of 2k items.
I will have a look at CustomListview.

Regards

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