Customising a spinner

[ShamusVW]

I am working using Fragments and I pull data from a MySQL database and put it into an ArrayList.
I then populate the Spinner with the returned data.
What I can't seem to figure out is how to customize that Spinner holding the data using the ArrayList I already have.

I define a spinner in my onCreateView as"

private Spinner spinner;
@Nullable
@Override
public View onCreateView(@NonNull LayoutInflater inflater, @Nullable ViewGroup container, @Nullable Bundle savedInstanceState) {
    View view = inflater.inflate(R.layout.fragment_training_layout, container, false);
    spinner = (Spinner) view.findViewById(R.id.spinnerTrainers);
…

This is my class to extract the data, and how I am populating the Spinner:

   private class ConnectMySql extends AsyncTask<String, Void, String> {
        List<String> trainers = new ArrayList<String>();
        ArrayAdapter<String> adapter;

        @Override
        protected void onPreExecute() {
            super.onPreExecute();
        }

        @Override
        protected String doInBackground(String... params) {
            try {
                Class.forName("com.mysql.jdbc.Driver");
                Connection con = DriverManager.getConnection(url, user, pass);

                Statement st = con.createStatement();
                ResultSet rs = st.executeQuery("SELECT * FROM pdc_production.die_detail");
                ResultSetMetaData rsmd = rs.getMetaData();

                while (rs.next()) {
                    trainers.add(rs.getString(1).toString() + ":" + rs.getString(2).toString());
                }
            } catch (Exception e) {
                e.printStackTrace();
            }
            return "";
        }

        @Override
        protected void onPostExecute(String result) {
            adapter = new ArrayAdapter<String> (getContext(), android.R.layout.simple_spinner_dropdown_item, trainers);
//            adapter = ArrayAdapter.createFromResource(getContext(), trainers, android.R.layout.simple_spinner_dropdown_item);
            spinner.setAdapter(adapter);
        }

    }

This line populates the Spinner

adapter = new ArrayAdapter<String> (getContext(), android.R.layout.simple_spinner_dropdown_item, trainers)

The line right beneath it (commented out)

adapter = ArrayAdapter.createFromResource(getContext(), trainers, android.R.layout.simple_spinner_dropdown_item)

is the line that I can't quite figure out how to do it. The examples I have looked at show an Array being used, but I already have the ArrayList called trainers, so I don't know how to make use of it instead of creating another array.
Could someone assist me please?

Right now this is what my spinner looks like, very boring!

 

[wseng92]

I would suggest you to create custom ArrayAdapter like this:

https://www.worldbestlearningcenter.com/tips/Android-populate-spinner-from-mysql-database.htm

 

[ShamusVW]

Thank you for the reply, only now got to looking at that link.
I tried creating a new layout called "spinner_layout.xml" as in the example.
I also changed my List type to an ArrayList type

List<String> trainers = new ArrayList<String>();

changed to...

ArrayList<String> trainers = new ArrayList<String>();

I am able to populate my ArrayList with items from my query, that isn't the problem.
I just have a problem trying to alter my spinner. The Array in R.Array.spinners stays red in the code below

private class ConnectMySql extends AsyncTask<String, Void, String> {
...
@Override
protected void onPostExecute(String result) {
    adapter = ArrayAdapter.createFromResource(getContext(), R.Array.trainers, R.layout.spinner_layout);
    spinner.setAdapter(adapter);
}
}

 

[ShamusVW]

So I figured this out, and it looks like I could make this work.
So in my class ConnectMySql in the onPostExcute method I have the following:

@Override
protected void onPostExecute(String result) {
    ArrayAdapter<String> adapter = new ArrayAdapter<String>(getActivity(),R.layout.spinner_layout, trainers);
    spinner.setAdapter(adapter);
}

The only change is changing the "android.R.layout.simple_spinner_dropdown_item" to "R.layout.spinner_layout", and then creating a layout_spinner.xml file.
This was the original line:

adapter = new ArrayAdapter<String> (getContext(), android.R.layout.simple_spinner_dropdown_item, trainers);

The layout_spinner.xml file:

<?xml version="1.0" encoding="utf-8"?>
    <TextView xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@android:id/text1"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:textAppearance="?android:attr/textAppearanceListItemSmall"
    android:gravity="center_vertical"
    android:paddingStart="?android:attr/listPreferredItemPaddingStart"
    android:paddingEnd="?android:attr/listPreferredItemPaddingEnd"
    android:minHeight="?android:attr/listPreferredItemHeightSmall"
    android:paddingLeft="?android:attr/listPreferredItemPaddingLeft"
    android:background="@color/logoGreen"
    android:paddingRight="?android:attr/listPreferredItemPaddingRight" />

Although it doesn't give me yet what I am wanting, it is just now a matter of changing this layout_spinner.xml to what I need.