Preferences - (4) sharedPreference 에서 값 가져오기

Preferences3.zip

0. Result

   

1. Using PreferenceManager, get the default SharedPreference

   Set setTextView() based on the value from the SharedPreference

MainActivity.java

package com.tistory.qlyh8.preferences;
 
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.preference.PreferenceManager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
 
public class MainActivity extends AppCompatActivity {
 
    TextView textView1, textView2;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        textView1 = findViewById(R.id.text1);
        textView2 = findViewById(R.id.text2);
 
        setupSharedPreferences();
    }
 
    // text1 세팅 (Shown / Hidden)
    private void setTextView1(boolean isTrue){
        if(isTrue)
            textView1.setText("Text1");
        else
            textView1.setText("");
    }
 
    // text2 세팅 (Shown / Hidden)
    private void setTextView2(boolean isTrue){
        if(isTrue)
            textView2.setText("Text2");
        else
            textView2.setText("");
    }
 
    // SharedPreferences 에서 모든 값을 가져 와서 설정
    private void setupSharedPreferences() {
        SharedPreferences sharedPreferences
                = PreferenceManager.getDefaultSharedPreferences(this);
 
        // text1 세팅 (Shown / Hidden)
        setTextView1(sharedPreferences.getBoolean(getString(R.string.pref_show_text1_key),
                getResources().getBoolean(R.bool.pref_show_text1_default)));
 
        // text2 세팅 (Shown / Hidden)
        setTextView2(sharedPreferences.getBoolean(getString(R.string.pref_show_text2_key),
                getResources().getBoolean(R.bool.pref_show_text2_default)));
 
        /*SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putBoolean(getString(R.string.pref_show_text1_key), getResources().getBoolean(R.bool.pref_show_text1_default));
        editor.apply();*/
    }
...
}
 

2. Implement OnShardPreferenceChangeListener

   Override the onSharedPreferenceChanged method and update the show textView preference

   Register the listener

   Override onDestory and unregister the listener

MainActivity.java

package com.tistory.qlyh8.preferences;
 
import android.content.Intent;
import android.content.SharedPreferences;
import android.support.v7.app.AppCompatActivity;
import android.os.Bundle;
import android.support.v7.preference.PreferenceManager;
import android.view.Menu;
import android.view.MenuItem;
import android.widget.TextView;
 
public class MainActivity extends AppCompatActivity implements SharedPreferences.OnSharedPreferenceChangeListener {
 
    TextView textView1, textView2;
 
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_main);
 
        textView1 = findViewById(R.id.text1);
        textView2 = findViewById(R.id.text2);
 
        setupSharedPreferences();
    }
 
    // text1 세팅 (Shown / Hidden)
    private void setTextView1(boolean isTrue){...}
 
    // text2 세팅 (Shown / Hidden)
    private void setTextView2(boolean isTrue){...}
 
    // SharedPreferences 에서 모든 값을 가져 와서 설정
    private void setupSharedPreferences() {
        SharedPreferences sharedPreferences
                = PreferenceManager.getDefaultSharedPreferences(this);
 
        // text1 세팅 (Shown / Hidden)
        setTextView1(sharedPreferences.getBoolean(getString(R.string.pref_show_text1_key),
                getResources().getBoolean(R.bool.pref_show_text1_default)));
 
        // text2 세팅 (Shown / Hidden)
        setTextView2(sharedPreferences.getBoolean(getString(R.string.pref_show_text2_key),
                getResources().getBoolean(R.bool.pref_show_text2_default)));
 
        /*SharedPreferences.Editor editor = sharedPreferences.edit();
        editor.putBoolean(getString(R.string.pref_show_text1_key), getResources().getBoolean(R.bool.pref_show_text1_default));
        editor.apply();*/
 
        // 리스너 등록
        // 리스너를 implement 해주었기 때문에 this
        sharedPreferences.registerOnSharedPreferenceChangeListener(this);
    }
 
    // shared preferences 이 변경되면 화면을 업데이트
    // OnSharedPreferenceChangedListener 를 구현하는 클래스를 만들 때 이 메서드가 필요
    @Override
    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
        if(key.equals(getString(R.string.pref_show_text1_key))) {
            setTextView1(sharedPreferences.getBoolean(key, getResources().getBoolean(R.bool.pref_show_text1_default)));
        }
        else if(key.equals(getString(R.string.pref_show_text2_key))) {
            setTextView2(sharedPreferences.getBoolean(key, getResources().getBoolean(R.bool.pref_show_text2_default)));
        }
    }
 
    @Override
    protected void onDestroy() {
        super.onDestroy();
        //리스너 해지
        PreferenceManager.getDefaultSharedPreferences(this)
                .unregisterOnSharedPreferenceChangeListener(this);
    }
 
    //메뉴 생성
    @Override
    public boolean onCreateOptionsMenu(Menu menu) {...}
 
    //메뉴의 항목이 선택되었을 때 호출
    @Override
    public boolean onOptionsItemSelected(MenuItem item) {...}
}
 

Android Course of Udacity - Lesson 6