[Android] Menu xml

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"
    android:id="@+id/baseLayout"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="오른쪽 위 메뉴 버튼을 누르세요" />
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="이건 버튼">
    </Button>

</LinearLayout>

menu1.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"
    android:id="@+id/baseLayout"
    tools:context=".MainActivity">

    <TextView
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="오른쪽 위 메뉴 버튼을 누르세요" />
    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="이건 버튼">
    </Button>

</LinearLayout>

MainActivity.java

package com.example.menu;

import androidx.annotation.NonNull;
import androidx.appcompat.app.AppCompatActivity;

import android.annotation.SuppressLint;
import android.graphics.Color;
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);


    }

    @SuppressLint("NonConstantResourceId")
    @Override
    public boolean onOptionsItemSelected(@NonNull MenuItem item) {
        switch(item.getItemId()){
            case R.id.itemRed:
                baseLayout.setBackgroundColor(Color.RED);
                return true;
            case R.id.itemBlue:
                baseLayout.setBackgroundColor(Color.BLUE);
                return true;
            case R.id.itemGreen:
                baseLayout.setBackgroundColor(Color.GREEN);
                return true;
            case R.id.subRotate:
                button1.setRotation(45);
                return true;
            case R.id.subSize:
                button1.setScaleX(2);
                return true;
        }
        return super.onOptionsItemSelected(item);
    }
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {
        super.onCreateOptionsMenu(menu);
        MenuInflater mInflater=getMenuInflater();
        mInflater.inflate(R.menu.menu1,menu);
        return super.onCreateOptionsMenu(menu);
    }
}

배운 점

menu은 보통 고정되어 변하지 않기 때문에 xml에서 코드를 구현해 주는 것이 좋다. menu를 만들 때, res파일에서 menu.xml파일을 따로 만들어 줘야 하며 java파일에서 onCreateOptionsMenu와 onOptionsItemSelected를 onCreate함수 밖에 오버 라이딩해줘야 하는데 menu를 만들 때 거의 고정된 방식이므로 기억해 두도록 하자.

 

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