[안드로이드 프로그래밍 7판] 실습 7-1 배경색 바꾸기 앱 만들기

activity_main.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:tools="http://schemas.android.com/tools"
    xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent"
    android:layout_height="match_parent">

    <LinearLayout
        android:id="@+id/baseLayout"
        android:layout_width="match_parent"
        android:layout_height="match_parent"
        android:gravity="center"
        >

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

    </LinearLayout>


</LinearLayout>

 

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="초록색">

    </item>
    <item
        android:id="@+id/itemBlue"
        android:title="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>

 

MainActivity.java

package com.example.myapplication;

import androidx.appcompat.app.AppCompatActivity;

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
    public 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);
    }

    public boolean onCreateOptionsMenu(Menu menu){
        super.onCreateOptionsMenu(menu);
        MenuInflater menuInflater = getMenuInflater();
        menuInflater.inflate(R.menu.menu_1, menu);
        return true;
    }

    public boolean onOptionsItemSelected(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 false;
    }


}

 

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