MainActivity.java
package com.cfsuman.androidtutorials;
import android.app.Activity;
import android.os.Bundle;
import android.widget.ArrayAdapter;
import android.widget.Button;
import android.widget.Spinner;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;
public class MainActivity extends Activity {
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
// Get the widgets reference from XML layout
Button button = findViewById(R.id.button);
Spinner spinner = findViewById(R.id.spinner);
// Initializing a String Array
String[] plants = new String[]{
"Laceflower",
"Sugar maple",
"Mountain mahogany",
"Butterfly weed",
"Carrot weed"
};
// Convert array to a list
List<String> plantsList = new ArrayList<>
(Arrays.asList(plants));
// Initializing an ArrayAdapter
ArrayAdapter<String> spinnerArrayAdapter
= new ArrayAdapter<String>(
this,
android.R.layout.simple_spinner_dropdown_item,
plantsList
);
// Set the drop down view resource
spinnerArrayAdapter.setDropDownViewResource(
android.R.layout.simple_dropdown_item_1line
);
// Finally, data bind the spinner object with adapter
spinner.setAdapter(spinnerArrayAdapter);
// Set the button click listener
button.setOnClickListener(v -> {
// Remove item/element from List index zero
// Remove first item of List
if (!plantsList.isEmpty()){
plantsList.remove(0);
spinnerArrayAdapter.notifyDataSetChanged();
}
});
}
}
activity_main.xml
<?xml version="1.0" encoding="utf-8"?>
<androidx.constraintlayout.widget.ConstraintLayout
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"
android:background="#DCDCDC"
android:padding="24dp">
<Button
android:id="@+id/button"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:text="Remove First Item From Spinner"
android:textAllCaps="false"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toTopOf="parent" />
<Spinner
android:id="@+id/spinner"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_marginTop="16dp"
app:layout_constraintStart_toStartOf="parent"
app:layout_constraintTop_toBottomOf="@+id/button" />
</androidx.constraintlayout.widget.ConstraintLayout>

