Spinner
===

package com.example.myapplication2;

import androidx.appcompat.app.AppCompatActivity;

import android.os.Bundle;
import android.view.View;
import android.widget.AdapterView;
import android.widget.ArrayAdapter;
import android.widget.GridView;
import android.widget.Spinner;
import android.widget.Toast;

public class MainActivity extends AppCompatActivity {


    private String[] fruits = {"Apple","Banana","Orange","Grape","Strawberry"};

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);

        Spinner spinner = (Spinner) findViewById(R.id.spinner);

        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                MainActivity.this,
                android.R.layout.simple_list_item_1,
                fruits
        );
        adapter.setDropDownViewResource(android.R.layout.simple_list_item_1);
        spinner.setAdapter(adapter);

        spinner.setOnItemSelectedListener(new Spinner.OnItemSelectedListener() {
            @Override
            public void onItemSelected(AdapterView<?> parent, View view, int position, long id) {
                String msg = parent.getItemAtPosition(position).toString();
                Toast.makeText(MainActivity.this, msg, Toast.LENGTH_SHORT).show();
            }

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

            }
        });
    }
}

<?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"
    tools:context=".MainActivity">

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</androidx.constraintlayout.widget.ConstraintLayout>


## Ref.
[https://ithelp.ithome.com.tw/articles/10220610](https://ithelp.ithome.com.tw/articles/10220610)

###### tags: `介紹`