서브액티비티에서 메인액티비티로 값 가져오기

시작 액티비티에서 서브 액티비티로 이동 후, 

서브 액티비티에서 입력한 내용을 시작 액티비티로 옮기는 예제

1. 메인 액티비티 레이아웃

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.progdv.startactivityforresult.MainActivity">

    <LinearLayout
        android:orientation="vertical"
        android:layout_width="match_parent"
        android:layout_height="match_parent">
        
        <Button
            android:id="@+id/btn1"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_marginBottom="25sp"
            android:text="서브 액티비티 호출"
            />

        <TextView
            android:layout_width="wrap_content"
            android:layout_height="wrap_content"
            android:text="리턴받은 문자열(아래쪽)" />

        <TextView
            android:id="@+id/result"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:padding="25sp"
            android:textColor="#ff0000"
            android:text="이곳에 출력하세요"
             />

    </LinearLayout>
    
    

</RelativeLayout>

2. 서브 액티비티인 result activity 생성 후 레이아웃 설정

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout 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:paddingBottom="@dimen/activity_vertical_margin"
    android:paddingLeft="@dimen/activity_horizontal_margin"
    android:paddingRight="@dimen/activity_horizontal_margin"
    android:paddingTop="@dimen/activity_vertical_margin"
    tools:context="com.progdv.startactivityforresult.ResultActivity">

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

<EditText
    android:id="@+id/edit"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="이곳에 리턴할 문자를 입력하세요."
    />

        <LinearLayout
            android:id="@+id/linearLayout"
            android:orientation="horizontal"
            android:layout_width="match_parent"
            android:layout_height="wrap_content"
            android:layout_gravity="center"
            >
    <Button
        android:id="@+id/btn_ok"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
        android:text="입력 완료"
        android:layout_weight="1"
        />

            <Button
                android:id="@+id/btn_cancel"
                android:layout_width="wrap_content"
                android:layout_height="wrap_content"
                android:text="취소"
                android:layout_weight="1"
                />
        </LinearLayout>

    </LinearLayout>

</RelativeLayout>

3. 메인 액티비티 클래스

package com.progdv.startactivityforresult;

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.TextView;

public class MainActivity extends AppCompatActivity {

    Button btn;
    TextView result;

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

        btn = (Button)findViewById(R.id.btn1);
        result = (TextView)findViewById(R.id.result);
        btn.setOnClickListener(new View.OnClickListener() {
            @Override
            public void onClick(View v) {
                Intent intent =
                        new Intent(MainActivity.this, ResultActivity.class);
                //startActivity(intent);
                startActivityForResult(intent, 1);
            }
        });
    }

    @Override
    protected void onActivityResult(int requestCode, int resultCode, Intent data) {
        // super.onActivityResult(requestCode, resultCode, data);
        if(requestCode == 1) {
            if(resultCode == RESULT_OK) {
                String str = data.getStringExtra("INPUT_TEXT");
                result.setText(str);
            }else if(resultCode == RESULT_CANCELED) {
                // 취소 버튼 클릭
            }
        }
    }
}

4. 서브 액티비티 ResultActivity 클래스 

package com.progdv.startactivityforresult;

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;
import android.widget.EditText;

public class ResultActivity extends AppCompatActivity {

    EditText edit;
    Button btn_ok, btn_cancel;

    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_result);

        edit = (EditText)findViewById(R.id.edit);
        btn_ok = (Button)findViewById(R.id.btn_ok);
        btn_cancel = (Button)findViewById(R.id.btn_cancel);

        btn_ok.setOnClickListener(new View.OnClickListener(){
            @Override
            public void onClick(View v) {
                Intent intent = new Intent();
                intent.putExtra("INPUT_TEXT", edit.getText().toString());
                setResult(Activity.RESULT_OK, intent);
                finish();
            }
        });

    }
}

서브에서 입력한 값이 메인으로 잘 넘어온다.