Btukfyl

How can I implement SharedPreference in my Adapter class?
I want to use it for persisting CheckBox state. Now the CheckBox value unchecks itself when I change Activity or add a new item in the ListView.

public class listItems extends ArrayAdapter<Items> {



Activity context;

List<Items> listitems;



public listItems(Activity context, List<Items> listitems) {

    super(context, R.layout.list_items, listitems);

    this.context = context;

    this.listitems = listitems;

}



@NonNull

@Override

public View getView(final int position, @Nullable View convertView, @NonNull ViewGroup parent) {

    LayoutInflater inflater = context.getLayoutInflater();





    View listViewItem = inflater.inflate(R.layout.list_items, null, true);





    final Items items = listitems.get(position);



    final TextView tvitemname = (TextView) listViewItem.findViewById(R.id.tvitemname);



    final CheckBox simpleCheckedTextview = (CheckBox) listViewItem.findViewById(R.id.cb);

    tvitemname.setText(items.getItemname());

    simpleCheckedTextview.isChecked();









    return listViewItem;

}

I've added my Items class. Is this looking good? I have a TextView that gets data from FireBase.

Class:

public class Items {



String itemId;

String itemname;

private boolean checked;



public Items(){



}





public Items(String itemId, String itemname, boolean checked) {

    this.itemId = itemId;

    this.itemname = itemname;

    this.checked = checked;

}









public String getItemId() {

    return itemId;

}



public String getItemname() {

    return itemname;



}



public void setChecked(boolean checked) {

    this.checked = checked;

}



public boolean isChecked() {

    return checked;

}

How can I implement SharedPreference in my adapter class:

Save:

SharedPreferences sharedPreferences =  context.getSharedPreferences("checkboxpref", 0);

SharedPreferences.Editor editor = sharedPreferences.edit();

editor.putBoolean("checkbox_value", true);

editor.apply();

Get:

SharedPreferences sharedPreferences =  context.getSharedPreferences("checkboxpref", 0);

final boolean getShared = sharedPreferences.getBoolean("checkbox_value", false);

I suppose you are new in Android development, so I advise you to start working with RecyclerView instead ListView. This is a good article to help you handle checkBox states on RecyclerViewAdapters.

The way adapters handles states for each item is totally different from how the Activity does. Once you scroll and the items are not visible they are destroyed and recreated again only when visible. That’s why you need to store the state of all values at least in memory with a Map or a SparseArray for example. Just follow step by step the link and it will work.

Do you want to persist this data related to a specific user even in different devices? If yes you should send it to your Firebase, otherwise just save it locally. You can use SharedPreferences, Room, Realm or any other local storage.