Android SharedPreferences example

Android에서 SharedPreferences 를 이용하여 Activity가 정지되기 전에 상태 값을 저장하고 다시 복원하는 예 

애플리케이션 영역에 저장되므로 애플리케이션이 삭제되면 함께 삭제됨 

main.xml

<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="wrap_content" 
    android:orientation="vertical">

    <TextView
        android:id="@+id/textView1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="@string/hello_world"
        tools:context=".MainActivity" />

    <EditText
        android:id="@+id/editText1"
        android:layout_width="match_parent"
        android:layout_height="wrap_content"
        android:ems="10" >

        <requestFocus />
    </EditText>

    <Button
        android:id="@+id/button1"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:text="Go Google" 
        android:onClick="onBtnGoogle"/>

</LinearLayout>

Activity

package com.example.androidapp;


import android.app.Activity;
import android.content.Intent;
import android.content.SharedPreferences;
import android.net.Uri;
import android.os.Bundle;
import android.view.View;
import android.widget.*;

public class TestActivity extends Activity {
	TextView tv;
	EditText editMsg;
	
	@Override
	protected void onCreate(Bundle savedInstanceState) {
		super.onCreate(savedInstanceState);
		setContentView(R.layout.main); 
		tv = (TextView) findViewById(R.id.textView1);
		editMsg = (EditText) findViewById(R.id.editText1);
	}

	public void onBtnGoogle(View v) {
		Intent intent = new Intent(Intent.ACTION_VIEW);
		intent.setData(Uri.parse("http://google.co.kr"));
		startActivity(intent);
	}
	
	@Override
	protected void onSaveInstanceState(Bundle outState) {
		super.onSaveInstanceState(outState);
		Toast.makeText(this, "onSaveInstanceState()...", Toast.LENGTH_SHORT).show();
	}
	
	@Override
	protected void onRestoreInstanceState(Bundle savedInstanceState) {
		super.onRestoreInstanceState(savedInstanceState);
		Toast.makeText(this, "onRestoreInstanceState...", Toast.LENGTH_SHORT).show();
	}
	
	@Override
	protected void onPause() {
		String msg = editMsg.getText().toString();
		SharedPreferences sp = null;
		sp = getSharedPreferences("Pref01", Activity.MODE_PRIVATE);
		SharedPreferences.Editor editor = sp.edit();
		editor.putString("msg", msg);
		editor.commit();
		super.onPause();
	}
	
	@Override
	protected void onResume() {
		super.onResume();
		SharedPreferences sp = null;
		sp = getSharedPreferences("Pref01", Activity.MODE_PRIVATE);
		if(sp!=null && sp.contains("msg")) {
			String msg = sp.getString("msg", "");
			tv.setText(tv.getText().toString()+msg);
		}
	}
}