Fetching information from server and assign required data to Spinner using Retrofit

Question

How to fetch information from server and assign that data to Spinner using retrofit and Gson converter?

Gradle

   dependencies {
        implementation 'com.squareup.retrofit2:retrofit:2.5.0'
        implementation 'com.squareup.retrofit2:converter-gson:2.5.0'
    }

PhP code

<?php

require "con.php";

$sql = "SELECT * FROM Tbl_cross";
$result = mysqli_query($con,$sql);
$response = array();

while ($row = mysqli_fetch_array($result))
{
    array_push($response,array('cross'=>$row['school_cross']));
}

echo json_encode ($response);
mysqli_close($con);

?>

XML code

<?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout
    android:background="#d0d0f7"
    xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent">


        <Spinner
            android:id="@+id/spinner"
            android:layout_width="368dp"
            android:layout_height="wrap_content"
            android:layout_marginStart="8dp"
            android:layout_marginLeft="8dp"
            android:layout_marginTop="8dp"
            android:layout_marginEnd="8dp"
            android:layout_marginRight="8dp"
            android:layout_marginBottom="8dp"
            app:layout_constraintBottom_toBottomOf="parent"
            app:layout_constraintEnd_toEndOf="parent"
            app:layout_constraintHorizontal_bias="0.0"
            app:layout_constraintStart_toStartOf="parent"
            app:layout_constraintTop_toTopOf="parent"
            app:layout_constraintVertical_bias="0.015" />

</android.support.constraint.ConstraintLayout>

Answer 1

1.Firstly get data from the response, which you want to set in spinner. For example, show the list of dates.

private ArrayList<String> datesList=new ArrayList<>();
datesList.addAll(response.body().getData());
setDatesSpinner();

2.Call setDatesSpinner method for setting data in spinner.

private void setDatesSpinner() {
    ArrayAdapter<String> datesAdapter = new ArrayAdapter<String>(this, R.layout.item_progress_date_list, datesList);
    pro_date_spinner.setAdapter(datesAdapter);
    pro_date_spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {

        }
        @Override
        public void onNothingSelected(AdapterView<?> parent) {

        }
    });
}