I am working on an Android app that will allow the user to see restaurants in the city I live in. I am storing each restaurants information (name, address, telephone, hours, category, website) in an SQLite database.
What I am trying to do is to create a SortByAlpha activity that will list the restaurants by name in alphetically-descending order.
I understand that I should be using a Cursor to do this but I can't find a half decent tutorial, all of the "tutorials" I find are a bunch of code with minimal explanation. How can I do this / Where can I find a good tutorial?
Use SimpleCursorAdapter, which bridges between Cursor and Adapter. Here is an example how to use it: http://developer.android.com/guide/topics/ui/binding.html
I would advise creating a "Restaurant" class that contains all the fields you will be listing. Then make your SQL call and specify "ORDER BY Name". Then create an ArrayList that can be fed to your custom list adapter! Also, if they were to somehow get out of order, just implement the "Comparable" interface for the Restaurant class and compare based on "Name" and then you can call Collections.sort(restaurantlist); to sort them in alphabetical order. I personally think ORDER BY is the easier way to go!
Related
I have a ContentProvider implementation in my app which works fine. I have a table called elements where the user can store a bunch of information.
What I am doing is when the user opens the app, I pull this data out of the database, process it using the display options set by the user (Like change the string formats, time formats, date formats, number decimals etc), and then put it in ListFragment which using my own implementation of ArrayAdapter. User can of course change the preferences in the middle of the session, where I reload the data and reformat it and present it to the user. The user can click on an item in the list, and see more details of that item. I accomplish this by overriding ListFragment.onListItemClick().
I have been reading about SimpleCursorAdapter. I am confused if the use of this would be more correct than using an ArrayAdapter for what I am doing. I am confused because I am not directly mapping the database data to the view. So should I be using a SimpleCursorAdapter? Also, the _ID column seems to be a requirement. I don't want to rename my table at this point. After a few articles and tutorials, I am not sure what to do. So any suggestions are appreciated.
I am looking for some help to find a powerfull way to allow selection of different List items.
My case is that i have for exemple a List profiles, List teams ... and i'd like to have an autocomplete input that will show, for exemple if i type Al, all Teams and Profiles objects having there member variable name begining by Al.
The result would be that i could get from the activity, on submit click performed, a List & a List containing all the objects who have been selected through the autocomplete form.
Also i'd like that the list offered to the user that match the chars he typed show the name and a picture (facebook like tag selection).
Obviously i am not asking for some code but at least some guidelines from experienced Android devs who know what to do and not to do to create this kind of thing.
Thanks
Loader are one of the best way to filter list. You init a loader which take the String constraint used for filter, the each time the user type, you update the constraint and restart your Loader.
If I suppose that all your object are cached in a SQLite database you can use a CursorAdapter, Cursor and CursorLoader.
You create the needed CursorLoader by filter the query with the content of the EditText.
If you're not familiar with CursorLoader there is the AsyncTaskLoader, with this you won't have the need of DB and to code a provider which can accept raw query. Your object in ListA, ListB, etc must inherits of common class (hum... DataThing maybe :-)), you concatenate the objects in a list then you can filter the list : What is the best way to filter a Java Collection?
That's for the data filtering. Now in order to display the data the way you want, you can display of list below the EditText field or create a custom component if you want a more advanced look.
I'm designing an android app that retrieve universities from online database I have to use ExpandableListView to represent them. I have 700 universities so I need to represent them by category . My categories are by letters A,B,C,D etc.
>L
London Metropolitan University
Lea Valley College
>M
Manchester College
Manchester University
I have problem populating the child elements in each category. Because I have a lot of data I think the best way is when each category is pressed to create sql query to get all universities starting with 'A' for example BUT all ExpandableListView example I found use arraylists or hashmaps with a few elements.
Thanks in advance for your time.
You could probably use CursorTreeAdapter.
See getChildrendCursor method:
If you want to asynchronously query a provider to prevent blocking the UI, it is possible to return null and at a later time call setChildrenCursor(int, Cursor).
I'm making an application with a database of courses (of school) that the user is participating in. I want to display those courses in a list (im using listview) and use also the subitem (extra information of that course) of the listitems. I found a tutorial (http://www.softwarepassion.com/android-series-custom-listview-items-and-adapters/) that displays a list like I want but it uses a class to store the data in instead of a database. So the tutorial uses an arraylist of objects of that class. It would be a detour though if i had to put my information from my database into a class to put it in the list.
Does anyone have a clue how to solve this?
Thanks!
I found a beter way. By using a simple adapter and putting the values of the cursor in a hashmap in a arraylist. Found the idea from this site: http://eureka.ykyuen.info/2010/01/03/android-simple-listview-using-simpleadapter/
Here is a perfect tutorial for what you need. It shows you how to create a simple SQLite database and then populate a listview using the database.
SQLite Database creation and Listview Population Tutorial
Confused beginner here.
I'm extending the functionality of the android notepad tutorial program. I can successfully get the data from the sql to display in a list view and I can use the findNote function to get an individual note.
What I want to be able to do is extract an individual note AND all following notes in the table. I'd be happy with some way to iterate through the remaining notes (a puzzle for me because the rowIds are not sequential) but would also settle for designing a query that... I don't know, returns a String[] with the item with the matching id at position 0 and all subsequent items later in the array.
I'm sure there are a thousand ways to do this, I'm willing to take almost any of them. Please let me know if I need to clarify further.
Just looking at the NotesDbAdapter class in that tutorial, there doesn't appear to be any timestamp captured with the notes. You would need to extend the table structure to include this and update the createNote and updateNote methods to set that accordingly. Then you can write your SQL based upon that timestamp.
John