I've read multiple (a lot, actually) of questions here on StackOverflow and on other websites about which methods to override when making a CustomCursorAdapter, but I still don't understand.
Some say that getView() delegates directly to newView() and bindView(), so is therefore unnecessary in a CursorAdapter. However, it seems that using a getView() method is the only way to incorporate a ViewHolder.
My intention is to put a CheckBox in each row of my ListView, but I'm not sure how to deal with the view recycling.
Could somebody please clarify this for me? Thanks in advance.
Look at googleshelves project. They use a viewholder a newview and bindview. Personally I've always used getview.
Related
I learned about the recycling in ListView, GridView or any AdapterView and learned about it's best for performance and etc.
But i don't know is that (Recycling) is the default behavior in any ListView or should i override some methods and do that with myself.
I know about Customized ListView also, so in Customized ListView what is the case?
Yes, ListView recycles views as posted here:
https://stackoverflow.com/a/14108676/799162
But as #Gautam told you, if you use the ViewHolder pattern you will increase the CPU performance because the ListView isn't going to create a lot of Views it's going to reuse them, as explained here:
http://developer.android.com/training/improving-layouts/smooth-scrolling.html#ViewHolder
I'd like to make multi-level listview with custom layout, which is similar with the listview in Lucky Patcher App...
How I can do it?
ExpandableListView is probably what you're looking for. Simply extend SimpleExpandableListAdapter and override its getView() method. Use your custom view for child views and you should be good to go. Finally set the ExpandableListView adapter to what you extended. Let me know if that works for you.
This is good example. For me it takes modification, but the idea is clear.
Custom Expandable ListView Tutorial - Android Example
The question can be considered closed.
I know that BaseAdapter has a mechanism in order to recycle Views in a ListView for efficiency. But how does it work in CursorAdapter exactly? Is it the same thing? I haven't really found any documentation on this. The closest there was is with the World of ListView's google IO video, but that doesn't take into account CursorAdapter. Any advice on the matter would be much appreciated!
The getView() method is responsible for recycling the row views(it's the same thing as for a non cursor based adapter, just that it delegates the row construction and data binding to two different methods) and for moving the Cursor to the correct position.
I'm new to Android development and I was coding with ListView with a custom adapter. So far so good, then I wanted to use the same adapter with more than one listview, is that ok?
And when I override the method getView(), then I use the same resource to show the views (eg. R.id.show_view). Can I use different layouts in the same adapter? I don't know how to accomplish that.
I dont have the code here, sorry, it's more a question of whether it's a good practice to use the same adapter (eg. ArrayAdapter) to match various ListViews.
You can reuse class, but no instance of adapter. And you can create different views for every entry. But for sake of performance, you shall reuse view supplied to getView() whenever possible
I want to do something like mylistview.setElementsofView(0).getElementById.setColor("black");
currently the only way I know of doing this is setting up a custom list view adapter, setting up constructors, do conditional checks to see if view is populated, then do stuff in that view
this seems very convoluted, when other parts of the listview are so easily accessible.
is there some inherited function I can access in listview to allow me to access the elements of a particular view without a custom adapter?
Thanks for any insight
The short answer to your question:
is there some inherited function I can access in listview to allow me to access the elements of a particular view without a custom adapter?
unfortunately is no.
Why do you think setting up a custom adapter is so convoluted? Just make the customized adapter class a nested class within your activity. Most likely, you'd only be looking at overriding the getView() method. In the end, you'll spend a lot less time doing this than looking for a "simple" solution.
What about
myListView.getChild(index).setColor("black");