Android: How to bind spinner to custom object list?

kotlin:

data class User(
    var id: Long,
    var name : String? ){

    override fun toString(): String {
        return name
    }
}

Implementation

 mBinding.ddUser.setOnItemClickListener { parent, view, position, id ->
            val user = adapter.getItem(position)
            Log.i("idUser","${user?.idtoString()} - ${user?.name}")
        }

Here's the complete process in Kotlin:

the spinner adapter class:

class CustomSpinnerAdapter(
    context: Context,
    textViewResourceId: Int,
    val list: List<User>
) : ArrayAdapter<User>(
    context,
    textViewResourceId,
    list
) {
    override fun getCount() = list.size

    override fun getItem(position: Int) = list[position]

    override fun getItemId(position: Int) = list[position].report.toLong()

    override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
        return (super.getDropDownView(position, convertView, parent) as TextView).apply {
            text = list[position].name
        }
    }

    override fun getDropDownView(position: Int, convertView: View?, parent: ViewGroup): View {
        return (super.getDropDownView(position, convertView, parent) as TextView).apply {
            text = list[position].name
        }
    }
}

and use it in your activity/fragment like this:

spinner.adapter = CustomerSalesSpinnerAdapter(
            context,
            R.layout.cuser_spinner_item,
            userList
        )

**Easy & Simple Solution**

overide the below method in model class.


 @NonNull
 @Override
 public String toString() {
  return name; //whatever the value which you want to show in spinner list.
    }

Add the below line to set adapter.

spinner.setAdapter(new ArrayAdapter<ModelClassName>(getContext(),R.layout.item_spinner,list));

If you don't need a separated class, i mean just a simple adapter mapped on your object. Here is my code based on ArrayAdapter functions provided.

And because you might need to add item after adapter creation (eg database item asynchronous loading).

Simple but efficient.

editCategorySpinner = view.findViewById(R.id.discovery_edit_category_spinner);

// Drop down layout style - list view with radio button         
dataAdapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);

// attaching data adapter to spinner, as you can see i have no data at this moment
editCategorySpinner.setAdapter(dataAdapter);
final ArrayAdapter<Category> dataAdapter = new ArrayAdapter<Category>

(getActivity(), android.R.layout.simple_spinner_item, new ArrayList<Category>(0)) {


        // And the "magic" goes here
        // This is for the "passive" state of the spinner
        @Override
        public View getView(int position, View convertView, ViewGroup parent) {
            // I created a dynamic TextView here, but you can reference your own  custom layout for each spinner item
            TextView label = (TextView) super.getView(position, convertView, parent);
            label.setTextColor(Color.BLACK);
            // Then you can get the current item using the values array (Users array) and the current position
            // You can NOW reference each method you has created in your bean object (User class)
            Category item = getItem(position);
            label.setText(item.getName());

            // And finally return your dynamic (or custom) view for each spinner item
            return label;
        }

        // And here is when the "chooser" is popped up
        // Normally is the same view, but you can customize it if you want
        @Override
        public View getDropDownView(int position, View convertView,
                                    ViewGroup parent) {
            TextView label = (TextView) super.getDropDownView(position, convertView, parent);
            label.setTextColor(Color.BLACK);
            Category item = getItem(position);
            label.setText(item.getName());

            return label;
        }
    };

And then you can use this code (i couldn't put Category[] in adapter constructor because data are loaded separatly).

Note that adapter.addAll(items) refresh spinner by calling notifyDataSetChanged() in internal.

categoryRepository.getAll().observe(this, new Observer<List<Category>>() {

            @Override
            public void onChanged(@Nullable final List<Category> items) {
                dataAdapter.addAll(items);
            }
});

Do:

spinner.adapter = object: ArrayAdapter<Project>(
            container.context,
            android.R.layout.simple_spinner_dropdown_item,
            state.projects
        ) {
            override fun getDropDownView(
                position: Int,
                convertView: View?,
                parent: ViewGroup
            ): View {
                val label = super.getView(position, convertView, parent) as TextView
                label.text = getItem(position)?.title
                return label
            }

            override fun getView(position: Int, convertView: View?, parent: ViewGroup): View {
                val label = super.getView(position, convertView, parent) as TextView
                label.text = getItem(position)?.title
                return label
            }
        }