Develop Reference

DropdownList of ExposedDropdownMenu does not update

I am using a Exposed dropdownlist in the application which should work like Spinner but when the
new data is attached to the adapter (data downloaded from server)it does not show the updated data instead previous data is shown.

Have you called notifyDataSetChanged or notifyItemRangeInserted after changing adapter data?

update the list view when data changes

I am creating Android application for an IOT product .
I am uploading sensor data to an web serves developed in REST architecture.
web service is working perfectly .
I want show in real time that if sensor data changes.
I want retrive data and update the Textview
how can I do that?

For refreshing listview data,you need to use the following line of code,
adapter.notifyDataSetChanged();
where,
adapter = your listview adapter object
Write above line of code after you retrieve data from a server or local database.

You want to update a textview or a listview?
If it is that you want to keep adding new records to a list view, just add the items to the listview adapter as they come in and call youradapter.notifyDataSetChanged() so the listview updates its content.

Add this Code in your adapter list like :
Adapter_Constructer(List<String> data){
this.data=data;
notifyDataSetChanged();}
and then update it when u want
or just use :
adapter.notifyDataSetChanged();
in your response method.
or Reinitialize and reset adapter then call adapter.notifyDataSetChanged();

Android Sqlite and notifyChanged()

Can anyone help me in populating the values from database and show in listview using the notifychanged()

you do not need to refresh activity. after fetching data from database you update your ArrayList or something like that, and call notifiyDataSetChanged() and it is done.

How to update CustomListView item in Android using Model where the model data is downloaded from internet?

I have a CustomListView in my android app. Each item consists of two pieces of text which are to be retrieved from an online SQL database. I'm using a Model class called ListModel and a custom adapter called CustomAdapter. I'm using an Asynctask to download the model data from the internet. But the problem is that, adding of a ListModel object to my ArrayList is not working when I do it in the onPostExecute method of my Asynctask. So, the listview is not getting updated. How do I display the Model items on my Custom List as soon as they get downloaded? Is there any way to do that?

This type of problems occures when adapter not properly notify after data downloaded. Notify your adapter in postExecute by notifyDataSetChanged () method

Generally this is because notifyDataSetChanged() isn't called on the arrayadapter. (but stacktraces/your code would be helpful)
In addition, this is a prime use of an in-memory SQLite database (if you plan on doing any custom queries)
Or a full on-disk SQLite DB if you want to cache data.
(Adding a content provider(by just surrounding the SqliteDB) would also be nice if you want to abstract away some more and provide observers, etc. )

How to bind asynchrounously a ArrayList<Object> to a ListView?

I'm trying to bind some data to a ListView but instead of being data direct from the tables of a database I have already worked data. So what happens is that I do a query, do some calculations and populate an ArrayList and then need to have this data binded to an ListView.
What I thought at first was having this query and calculations inside the onCreateLoader so every time my database changed it would be notified and my array would be repopulated followed by the refresh of the ListView.
My problem is being the implementation of the necessary changes in the Loader and the ArrayAdapter. The Loader I'm used to is the CursorLoader + a SimpleCursorAdapter so I can only use Cursors Objects.
How can I proceed? Where should I look for a solution of this kind?
Thanks