Friends,
I need to fetch data from SQlite Db and set it on List View,it fetches data has well but the view showing on screen being empty,anybody help me to get the content to visible.
For simple String values use an ArrayAdapter, for custom UI on the lists, create your own Adapter and override the getView method.
Related
I didn't use parse query adapter, instead I made a custom adapter and passed all the text and images in that but Parse only loads 100 items. Can anyone tell me how to get to the next page of the database without using the parse query adapter?
This is a well known problem, the default limit is 100, you should use (saying that you have a query which is a ParseQuery object), you need to call the query.setLimit(int N) where N represents the number of results that you want returned .
I am populating ListView with data from database . To bind data i'm using a CursorAdapter My list view looks like this
And my db will get updated through web service on every five seconds so when ever the db get updated i need to reflect the change on my list view . As you see my first 2 items in ListView row is directly bind with the columns in db it will get automatically updated. But other items are calculated in user side. so how will other items can be updated ??
Did you try calling Adapter_Object.notifyDataSetChanged() ?
is it possible for a Spinner to return multiple values or class object on selected?
For example I have a Spinner of Laptop models. When selected I want it to return LaptopSpecs object that contains size, weight, processor, etc. Then use it to display the information in the view below it.
Thanks
Sorry, there is no multi-select Spinner. You are welcome to use a multi-select list AlertDialog to allow the user to make their selection(s), but you will need to decide for yourself how you want to render those selection(s) when the dialog is not on the screen.
It depends on how you are populating your spinner.
If you are pulling the data from a database in a cursor, what you are trying to do is easy.
As a matter of fact, using a database, there's a couple ways you can do it:
1) You simply pull all the necessary data you need to create the object into your cursor (kinda heavy load on the front end), and when a selection is made (fromthe single bit of data displayed in the spinner), you use the cursor position reference in the onItemSlected method to pull the related data from the cursor and pack it into your object.
2) You pull only the piece of data to display in the spinner and when a selection is made, use the database row id in the onItemSelected method to fetch the rest of the data for your object from the database.
The question posted in this thread asks how to update a ListView when the data has changed. It assumes, however, that the data that is modified in a ListView is stored in a database. Therefore, the ListView UI can be updated by simply calling requery() after the changes have been committed to the database.
What should one do when modified data of a ListView is not stored in a database?
For example, if each item in a ListView is showing the distance to a particular landmark based on the user's current GPS coordinates, what is the correct way to update the view with the updated distances as the user moves about? Should the distances simply be stored in the database as a matter of convenience, so that requery() will update the UI? This does not seem like the correct approach if it is not necessary to persist (frequently changing) GPS data.
Edit: To clarify, I'd specifically like to address the situation where some of the data is stored in a database (the coordinates of the landmarks, for example), however, the frequently changing data is computed on the fly (e.g., the distances).
ArrayAdapter can be used instead of CursorAdapter.
The notifyDataSetChanged() method can be used to tell the ListView to refresh itself by requerying the ArrayAdapter assigned to it.
I suggest using ArrayAdapter instead of CursorAdapter (which is used to populate a ListView based on cursor > database query)
ArrayAdapter
You should update the array data storing your coordinate data. When it changes call adapter.notifyDataSetChanged() to have your list updated with the latest array data
Hope that helps
I have a ListView which uses cursor adapter to show the records from database. When a new records is inserted in database ,it works great and shows that entry on top of ListView on requery.
Now I am facing problem when User scroll down the List, background thread call web service and brings old data. In this case when it does requery, old data is also getting appended on top of list which should append old data at the end of list.
What should i need to do differently, to add old data at the end of List rather than top ? do i need to change method of insertion when I am getting this old data ?
I think you need to store a date field in your bd table and make an ORDER BY in the query....