Develop Reference

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();

Use of adapter.notifyDataSetChanged()

I am very new to Android development. I am little confuse about the use of Adapter.notifyDataSetChanged() with ArrayAdapter and ListView. In my project, I am displaying all student in ListView with the help of an ArrayAdapter. The ArrayAdapter is getting the data (ArrayList) from local(Sqlite) database. further, the local database is getting the data from server whenever the server data is changed.
I created the adapter instance in onCreate() and I bound the Listview with it. Whenever the local database is changed, I am trying to refresh the ListView with notifyDataSetChanged() method but somehow its not working.

Kotlin clear an adapter

What is the best way to clear an adapter in Kotlin?
I was trying to clear a recyclerview and update the values.
I am using LoaderManager and I am kind of stuck in this state.

If you want update recyclerview after adding/removing data in your adapter use this code
If you use Arraylist to store the data objects then just clear your list and call notifyDataSetChanged.
dataList.clear()
recyclerView?.adapter?.notifyDataSetChanged()

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. )

AutoCompleteTextView, ArrayAdapter and notifyDataSetChanged()

I'm using an AutoCompleteTextView with an ArrayAdapter which works like supposed.
The problem is, that I have to change the Array with the Autocomplete-Values. Calling notifyDataSetChanged() doesn't help. No changes are shown.
Do you know something to get around this problem?

Do not modify the ArrayList and call notifyDataSetChanged() as it will have no effect on ArrayAdapters (implementation seems broken).
Use clear(), add(), insert(), and remove() directly on your ArrayAdapter instead of those methods on your ArrayList.

You need to add more details to the question but based on a guesstimate of you problem, I would say that there is some problem in the implementation.
notifyDataSetChanged() informs the view to reload the data. If the data set up methods in the ArrayAdapter reference an unchanged data entity, notifyDataSetChanged() will have not effect.
A custom adapter implementation that extends ArrayAdapter will generally have an internal data structure that is the source of data for the adapter and which will contain the AutoComplete values you require.