애플리케이션 구성요소와 액티비티 전환 (2)

0. 실행 결과 화면

    

1. AndroidManifest.xml

<?xml version="1.0" encoding="utf-8"?>
<manifest xmlns:android="http://schemas.android.com/apk/res/android"
    package="com.tistory.qlyh8.pracitice">
 
    <application
        android:allowBackup="true"
        android:icon="@mipmap/ic_launcher"
        android:label="@string/app_name"
        android:roundIcon="@mipmap/ic_launcher_round"
        android:supportsRtl="true"
        android:theme="@style/AppTheme">
        <activity android:name=".MainActivity">
            <intent-filter>
                <action android:name="android.intent.action.MAIN" />
 
                <category android:name="android.intent.category.LAUNCHER" />
            </intent-filter>
        </activity>
        <!-- 상단 화면 이름을 "서브 화면"으로, 아래와 같이 theme 를 설정하면 대화상자 화면으로 나온다. -->
        <activity
            android:name=".SubActivity"
            android:label="서브 화면"
            android:theme="@style/Base.Theme.AppCompat.Light.Dialog" />
    </application>
 
</manifest>

2. activity_main.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"
    xmlns:app="http://schemas.android.com/apk/res-auto"
    tools:context="com.tistory.qlyh8.pracitice.MainActivity"
    android:gravity="center">
 
   <Button
       android:id="@+id/button"
       android:layout_width="200dp"
       android:layout_height="wrap_content"
       android:text="화면전환" />
 
</LinearLayout>
 

3. activity_sub.xml

<?xml version="1.0" encoding="utf-8"?>
<android.support.constraint.ConstraintLayout 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"
    tools:context="com.tistory.qlyh8.pracitice.SubActivity">
 
    <Button
        android:id="@+id/button"
        android:layout_width="100dp"
        android:layout_height="wrap_content"
        android:text="돌아가기"
        app:layout_constraintTop_toTopOf="parent"
        app:layout_constraintLeft_toLeftOf="parent"
        app:layout_constraintRight_toRightOf="parent"
        app:layout_constraintBottom_toBottomOf="parent"/>
</android.support.constraint.ConstraintLayout>
 

4. SubActivity.java

package com.tistory.qlyh8.pracitice;
 
import android.app.Activity;
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
 
public class SubActivity extends AppCompatActivity {
 
    Button button;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_sub);
 
        button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("name", "Tom");
                setResult(Activity.RESULT_OK, intent);
                finish();
            }
        });
    }
}
 

5. MainActivity.java

package com.tistory.qlyh8.pracitice;
 
import android.content.Intent;
import android.os.Bundle;
import android.support.v7.app.AppCompatActivity;
import android.view.View;
import android.widget.Button;
import android.widget.Toast;
 
public class MainActivity extends AppCompatActivity {
 
    Button button;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        button = findViewById(R.id.button);
        button.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent = new Intent(getApplicationContext(), SubActivity.class);
                //startActivity(intent);
                startActivityForResult(intent, 101);    // 요청코드는 각각의 화면을 구분하는 구분자
 
                // ComponentName 객체를 만들어 설정하는 방법
                // 액티비티를 문자열로만 지정할 수 있어서 동적으로 액티비티를 지정해주고 싶을 때 사용할 수 있다.
                /*Intent intent = new Intent();
                ComponentName name = new ComponentName("qlyh8.tistory.com.pracitice",
                        "qlyh8.tistory.com.pracitice.SubActivity");
                intent.setComponent(name);
                startActivityForResult(intent, 101);*/
            }
        });
    }
 
    // 응답을 받아주는 메서드
    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == 101){
            Toast.makeText(getApplicationContext(), "Name: " + data.getStringExtra("name"),
                    Toast.LENGTH_LONG).show();
        }
    }
}
 

출처: https://www.edwith.org/boostcourse-android/lecture/17064/