안드로이드 이론 빡공 21

**activity_main.xml**

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout 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:orientation="vertical"
    tools:context=".MainActivity">

    <TextView
        android:id="@+id/textView"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="선택된 아이템"
        android:textSize="24sp" />

    <Spinner
        android:id="@+id/spinner"
        android:layout_width="match_parent"
        android:layout_height="wrap_content" />
</LinearLayout>

**MainActivity.java**

package com.threedpit.myspinner;

import androidx.appcompat.app.AppCompatActivity;

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

public class MainActivity extends AppCompatActivity {
    TextView textView;
    String[] items = {"kmp","ysk","jsh","msp","syc"};

    //
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        textView = findViewById(R.id.textView);
        Spinner spinner = findViewById(R.id.spinner);
        ArrayAdapter<String> adapter = new ArrayAdapter<String>(
                this,
                android.R.layout.simple_spinner_item,
                items
        );
        //이것은 spinner객체를 우리가 눌렀을때 선택하는 아이템들이 보이는 레이아웃을 의미
    adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
    spinner.setAdapter(adapter);

    spinner.setOnItemSelectedListener(new AdapterView.OnItemSelectedListener() {
        @Override
        //선택된 화면 텍스트뷰로 띄우기
        public void onItemSelected(AdapterView<?> adapterView, View view, int i, long l) {
            textView.setText(items[i]);
        }
        @Override
        //선택한것을 선택하지 않는 상태로 만드는것
        public void onNothingSelected(AdapterView<?> adapterView) {
            textView.setText("");
        }
    });
    }
}