[13] SharedPreferences

1. SharedPreferences

Activity

public class MainActivity extends AppCompatActivity { SharedPreferences pref; int num; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pref = PreferenceManager.getDefaultSharedPreferences( MainActivity.this ); num = pref.getInt("save", 0); }// onCreate() @Override protected void onDestroy() { super.onDestroy(); SharedPreferences.Editor edit = pref.edit(); edit.putInt("save", num); edit.commit(); } }

* getDefaultSharedPreferences() : 이전에 저장된 값 불러오기.

* getIntint("save", 0) : key 값이 save 인 정보를 불러온다. ( default : 0 )

* onDestroy(), onPause() 등 종료시에 호출 되는 메서드에서 값을 저장.

2. Tutorial ( SharedPreferences )

Layout (Main)

<?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:id="@+id/activity_main" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" 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.example.sin.sample_2.SubActivity" android:background="#aaf"> <TextView android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="tutorial" android:textSize="30dp" android:layout_centerInParent="true"/> <Button android:id="@+id/ok_btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="OK" android:layout_alignParentBottom="true"/> <CheckBox android:id="@+id/check" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Tutorial 다시보지 않기" android:layout_alignParentBottom="true" android:layout_alignParentRight="true"/> </RelativeLayout>

* 상태를 저장할 CheckBox 값에 의해 tutorial을 다시 볼지를 정하는 예제.

Activity (Main)

public class MainActivity extends AppCompatActivity { Button ok_btn; CheckBox check; SharedPreferences pref; boolean isTutorial; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_main); pref = PreferenceManager.getDefaultSharedPreferences( MainActivity.this); isTutorial = pref.getBoolean("tutorial", false); if(isTutorial) startIntent(); ok_btn = (Button)findViewById(R.id.ok_btn); check = (CheckBox)findViewById(R.id.check); ok_btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { SharedPreferences.Editor editor = pref.edit(); editor.putBoolean("tutorial", check.isChecked()); editor.commit(); startIntent(); } }); }//onCreate() private void startIntent() { Intent intent = new Intent(MainActivity.this, SubActivity.class); intent.setFlags( Intent.FLAG_ACTIVITY_CLEAR_TOP | Intent.FLAG_ACTIVITY_SINGLE_TOP); startActivity(intent); finish(); } }

* key값이 tutorial 인 boolean 값을 저장한다.

Layout (Sub)

<?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:id="@+id/activity_sub" android:layout_width="match_parent" android:layout_height="match_parent" android:orientation="vertical" 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.example.sin.sample_2.SubActivity"> <Button android:id="@+id/tutorial_btn" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="tutorial 다시보기" android:layout_alignParentBottom="true"/> </LinearLayout>

* tutorial 다시보지 않기를 체크후 닫았을 경우, 다시 tutorial을 표시 할수 있도록 하기 위해 추가.

Activity (Sub)

public class SubActivity extends AppCompatActivity { Button tutorial_btn; SharedPreferences pref; @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.activity_sub); pref = PreferenceManager.getDefaultSharedPreferences(SubActivity.this); tutorial_btn = (Button)findViewById(R.id.tutorial_btn); tutorial_btn.setOnClickListener(new View.OnClickListener() { @Override public void onClick(View view) { Intent intent = new Intent(SubActivity.this, MainActivity.class); SharedPreferences.Editor editor = pref.edit(); editor.putBoolean("tutorial", false); editor.commit(); startActivity(intent); } }); }// onCreate() }

* Intent로 화면 전환만 할경우, 기존에 저장된 값으로 인해 tutorial이 표시 되지 않음.

* 다시 보기를 할경우 key값이 tutorial 인 boolean 값을 false로 하여 다시 표시 하도록 변경.

3. 결과화면