[안드로이드 프로그래밍] 10장 직접 풀어보기 10-1

한빛아카데미 Android Studio를 활용한 안드로이드 프로그래밍 6판

 

p.397 직접 풀어보기 10-1

 

[실습 10-1]을 다음과 같이 수정하라.

• ThirdActivity를 추가한다.
• 라디오 버튼으로 선택된 액티비티가 나오게 한다.

 

코드

MainActivity.java

package com.cookandroid.test;

import androidx.appcompat.app.AppCompatActivity;
import android.content.Intent;
import android.os.Bundle;
import android.view.View;
import android.widget.Button;
import android.widget.RadioButton;

public class MainActivity extends AppCompatActivity {

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
        setTitle("메인 액티비티 (수정)");

        final RadioButton rdoSecond = findViewById(R.id.rdoSecond);

        Button btnNewActivity = (Button) findViewById(R.id.btnNewActivity);
        btnNewActivity.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                Intent intent;

                if (rdoSecond.isChecked() == true)
                    intent = new Intent(getApplicationContext(), SecondActivity.class);
                else
                    intent = new Intent(getApplicationContext(), ThirdActivity.class);

                startActivity(intent);
            }
        });
    }
}

 

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"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:orientation="vertical">

    <RadioGroup
        android:id="@+id/radioGroup1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content" >

        <RadioButton
            android:id="@+id/rdoSecond"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:checked="true"
            android:text="Second 액티비티" />

        <RadioButton
            android:id="@+id/rdoThird"
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="Third 액티비티" />
    </RadioGroup>

    <Button
        android:id="@+id/btnNewActivity"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="새 화면 열기" />

</LinearLayout>

 

SecondActivity.java

package com.cookandroid.test;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;

public class SecondActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.second);
        setTitle("Second 액티비티");

        Button btnReturn = findViewById(R.id.btnReturn);
        btnReturn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                finish();
            }
        });
    }
}

 

second.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#00FF00"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btnReturn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="돌아가기" />

</LinearLayout>

 

ThirdActivity.java

package com.cookandroid.test;

import android.os.Bundle;
import android.view.View;
import android.widget.Button;

import androidx.appcompat.app.AppCompatActivity;

public class ThirdActivity extends AppCompatActivity {

    @Override
    protected void onCreate(Bundle savedInstanceState) {

        super.onCreate(savedInstanceState);
        setContentView(R.layout.third);
        setTitle("Third 액티비티");

        Button btnReturn = findViewById(R.id.btnReturn);
        btnReturn.setOnClickListener(new View.OnClickListener() {
            public void onClick(View v) {
                finish();
            }
        });

    }
}

 

third.xml

<?xml version="1.0" encoding="utf-8"?>
<LinearLayout xmlns:android="http://schemas.android.com/apk/res/android"
    xmlns:tools="http://schemas.android.com/tools"
    android:layout_width="match_parent"
    android:layout_height="match_parent"
    android:background="#00FFFF"
    android:orientation="vertical" >

    <Button
        android:id="@+id/btnReturn"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:text="돌아가기" />

</LinearLayout>

 

형광펜 칠한 부분을 넣어주어야 오류가 나지 않는다.

 

결과