android - menu 추가하는 두가지 방법. (xml파일로 추가하기, 자바코드로 추가하기)

1. 메뉴 menu1.xml 로 메뉴추가

파일명 : activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/baseLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="키패드의 MENU 버튼을 누르세요"
        android:textSize="20dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id = "@+id/button1"
        android:text="이건 버튼" />
</LinearLayout>

파일명 : menu1.xml

<?xml version="1.0" encoding="utf-8"?>
<menu xmlns:android="http://schemas.android.com/apk/res/android">

    <item
        android:id="@+id/itemRed"
        android:title="배경색 (빨강)" >
    </item>
    <item
        android:id="@+id/itemGreen"
        android:title="배경색 (초록)" >
    </item>
    <item
        android:id="@+id/itemBlue"
        android:title="배경색 (파랑)" >
    </item>
    <item android:title="버튼 변경 >> ">
        <menu>
            <item
                android:id="@+id/subRotate"
                android:title="버튼 45도 회전" />
            <item
                android:id="@+id/subSize"
                android:title="버튼 2배 확대" />
        </menu>

    </item>

</menu>

파일명 : MainActivity.java

package com.example.it.myapplication7_1;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuInflater;
import android.view.MenuItem;
import android.widget.Button;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

    LinearLayout baseLayout;
    Button button1;

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

        baseLayout = (LinearLayout) findViewById(R.id.baseLayout);
        button1 = (Button) findViewById(R.id.button1);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        MenuInflater mInflater = getMenuInflater();
        mInflater.inflate(R.menu.menu1, menu);
        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case R.id.itemRed:
                baseLayout.setBackgroundColor(Color.RED);
                return true;
            case R.id.itemGreen:
                baseLayout.setBackgroundColor(Color.GREEN);
                return true;
            case R.id.itemBlue:
                baseLayout.setBackgroundColor(Color.BLUE);
                return true;
            case R.id.subRotate:
                button1.setRotation(45);
                return true;
            case R.id.subSize:
                button1.setScaleX(2);
                return true;
        }

        return super.onOptionsItemSelected(item);
    }
}

2. 자바코드로 메뉴 추가

파일명 : activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:id="@+id/baseLayout"
    android:layout_width="fill_parent"
    android:layout_height="fill_parent"
    android:gravity="center_horizontal"
    android:orientation="vertical">

    <TextView
        android:layout_width="fill_parent"
        android:layout_height="wrap_content"
        android:text="키패드의 MENU 버튼을 누르세요"
        android:textSize="20dp" />

    <Button
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:id = "@+id/button1"
        android:text="이건 버튼" />
</LinearLayout>

파일명 : MainActivity.java

package com.example.it.myapplication7_2;

import android.graphics.Color;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.view.Menu;
import android.view.MenuItem;
import android.view.SubMenu;
import android.widget.Button;
import android.widget.LinearLayout;

public class MainActivity extends AppCompatActivity {

    LinearLayout baseLayout;
    Button button1;

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

        baseLayout = (LinearLayout) findViewById(R.id.baseLayout);
        button1 = (Button) findViewById(R.id.button1);
    }

    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);

        menu.add(0, 1, 0, "배경색(빨강)");
        menu.add(0, 2, 0, "배경색(초록)");
        menu.add(0, 3, 0, "배경색(파랑)");

        SubMenu sMenu = menu.addSubMenu("버튼 변경 >>");
        sMenu.add(0, 4, 0, "버튼 45도 회전");
        sMenu.add(0, 5, 0, "버튼 2배 확대");

        return true;
    }

    @Override
    public boolean onOptionsItemSelected(MenuItem item) {
        switch (item.getItemId()) {
            case 1:
                baseLayout.setBackgroundColor(Color.RED);
                return true;
            case 2:
                baseLayout.setBackgroundColor(Color.GREEN);
                return true;
            case 3:
                baseLayout.setBackgroundColor(Color.BLUE);
                return true;
            case 4:
                button1.setRotation(45);
                return true;
            case 5:
                button1.setScaleX(2);
                return true;
        }
        return false;
    }
}