Menu
Is there an easy way to display a ListView in reverse order? I am trying to create a conversation-based app, and would like the most recent entries to be at the bottom of the ListView. I am aware of transcriptMode and stackFromBottom, however my problem is the order of the data.
Say I have 100 conversation items, and want to display items 80-100, with 100 being the most recent conversation item. I would like to show 80-100, which implies an ORDER BY id desc LIMIT 20 in my query, which forces the items to be sorted 100 to 80, the opposite of what I need. I currently have some nasty inner query code, but feel like there should be a simpler solution based on reversing the cursor or simply inverting the ListView.
433
To in-place reverse the order of the elements in a list, you can use the Collections. reverse() function. It takes the list whose elements are to be reversed.
A list view is an adapter view that does not know the details, such as type and contents, of the views it contains. Instead list view requests views on demand from a ListAdapter as needed, such as to display new views as the user scrolls up or down. In order to display items in the list, call setAdapter(android.
We can reverse a List in Dart either by using built-in functions or using looping statements with swap mechanism. Reversing a List makes the first element to be placed at last position, second element placed at last but one position and so on.
inside the baseAdapter, for the getView() method , instead of getting the item in the data in index "position" , use the opposite , meaning : numberOfItems minus the position .
as for showing the number of items , that's also inside the baseAdapter : set the value returned by getCount() to be the one you wish it to be (20 in your example,though 80-100 implies that it should be 21 ) .
btw, it seems you are a starter in the case of listView . may i suggest watching this video: http://www.youtube.com/watch?v=wDBM6wVEO70
also check the api-demos provided by the sdk manager . they have plenty of examples there.
56
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
