Develop Reference

why my onCreateViewHolder is calling all the items at a time?

I want to display thousand list items on a screen so I Created an adapter in that, onCreateViewHolder is calling all the items at a time.As it should call only some items at a time in recycled view.How to know where is the error?

list.getAdapter().getView(i, view, list) doesn't update my row

I have button in my row layout that on click toggles its state (and its background resource).
On its onClickListener I update the corresponding, to this row, data and I call the
list.getAdapter().getView(i, view, list);
The adapter getView is called (having the updated data) but it does not update visually my visible row. Any ideas why ?
Note that when I scroll down and then back scroll up the row is being updated.
PS1: Calling the adapter.notifyDataSetChanged() works but I do not want that since I want to update one single row.
PS2: I know that I could update the button of the row myself in its listener but I prefer to let the adapter do that for me, because the update of the row will become more complex later.

Calling
list.getAdapter().getView(i, view, list);
is wrong. The system takes care of calling getView to update/render the ListView's content. You have to update the dataset used to build the ListView's content up, and then call notifyDataSetChanged().

newview not invoke in ResourceCursorAdapter

I use ResourceCursorAdapter , first screen show 4 item， I scroll to bottom ,the 5 and next repeat ,in fact the fifth item is show the first item, I found is directly invoke bindview not newview,I don't know why?

It is because the fifth item is actually a recycled first item. Android recycles its list items for better performance. newView only called when the adapter want to inflate new view from XML file. So there is no guarantee that for every list item the newView will be called.

List view duplicate data

I am using list view to populate data in the custom dialog. I am passing a List to adapter. The list has 250 different items.
The problem I have is getView method of adapter is being called only 7 times and then the data is displayed in dialog. The dialog has first 7 items repeated to fill all the 250 rows in the dialog.
I couldn't understand why the getView is called only 7 times (and also in my dialog I can see 7 items at a time.. and i need to scroll to view other items. Is there any relation between the number of elements I see and number of times the getView will be called).
Any idea why it happens. Thanks in advance.

Yes, I think getView is called when the item is actually displayed on the screen. When you scroll, more items become visible and getView will be called more times.

i am creating new row only if convertView is null otherwise I return the same row. I couldn't understand why the data is duplicated in my dialog"
You can try to set the data of each item every time you return from getView method. convertView is reused, you need to update the data of the convertView bind of. You can use ViewHolder to save widgets in each item.

When is the getView() method of ListView called?

I'm working on ListView. I want to know when exactly getView() is called. Is it called once the adapter is set? And does the line next to "setting adapter" get called once the getView() method completes execution?
Please help me know which line gets executed once the getView() finishes execution.
That would be a great help for me.
Thanks in advance,
Vaishnvai

getView() is called for each item in the list you pass to your adapter.
It is called when you set adapter. When getView() is finished the next line after setAdapter(myAdapter) is called.
In order to debug getView() you must toggle a breakpoint on it because you can't step into getView() from setAdapter(myAdapter).
getView() is also called after notifyDataSetChanged() and on scrolling.

To be more clear, getView() is called whenever a new item is displayed on screen, at the count of displayed items. Which means, if you have 1 million items but 15 of them fits on screen, getView is called 15 times. Whenever you scroll up/down and new items appear, getView() is called for new ones. And you should be aware of recycler mechanism, too. Which holds a template item layout for each item type, and sends in this view to getView() method as convertView parameter, so you could use it in order to prevent layout inflation.