本文介绍SharedPreferences及PreferenceActivity、PreferenceFragment。

1、SharedPreferences简单使用示例

public class MainActivity extends Activity {private static final String TAG = MainActivity.class.getSimpleName();@Overrideprotected void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);getWindow().setContentView(R.layout.activity_main);//all apps sharing the same user IDSharedPreferences sp = getPreferences(Context.MODE_PRIVATE);SharedPreferences.Editor editor = sp.edit();//save 5 kinds of datas: boolean,int,long,float,Stringeditor.putBoolean("isMan", true);editor.putFloat("weight", 68f);editor.putInt("age", 25);editor.putLong("salary", 10000L);editor.putString("name", "Victor");Set<String> relatives = new HashSet<String>();editor.putStringSet("relatives", relatives);
//		editor.apply();//asynchronous,main threadlong start = SystemClock.elapsedRealtime();editor.commit();Log.i(TAG, "commit:"+(SystemClock.elapsedRealtime()-start)+"ms");}public void onClick(View v){switch (v.getId()) {case R.id.btn:Log.i(TAG, "getLocalClassName()="+getLocalClassName());SharedPreferences sp = getSharedPreferences(getLocalClassName(), Context.MODE_PRIVATE);sp.getBoolean("isMan", false);sp.getFloat("weight", 60);sp.getInt("age", 16);sp.getLong("salary", 6000L);sp.getString("name", "none");sp.getStringSet("relatives", null);Map<String, ?> map = sp.getAll();if(sp.contains("salary")){long salary = (Long) map.get("salary");Log.i(TAG, "contains:"+salary);}}}
}

<?xml version="1.0" encoding="utf-8"?>
<LinearLayoutandroid:layout_width="match_parent"android:layout_height="match_parent"android:orientation="vertical"xmlns:android="http://schemas.android.com/apk/res/android"><Button android:id="@+id/btn"android:layout_width="wrap_content"android:layout_height="wrap_content"android:text="get"android:onClick="onClick"/>
</LinearLayout>

2、PreferenceActivity、PreferenceFragment使用示例

1) MyFragmentPreferenceActivity.java

public class MyFragmentPreferenceActivity extends PreferenceActivity implements OnSharedPreferenceChangeListener{private static final String TAG = MyFragmentPreferenceActivity.class.getSimpleName();@Overridepublic void onBuildHeaders(List<Header> target) {super.onBuildHeaders(target);loadHeadersFromResource(R.xml.preferenceheaders, target);//getPackageName()+"_preferences"SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);sharedPreferences.registerOnSharedPreferenceChangeListener(this);}@Overridepublic void onSharedPreferenceChanged(SharedPreferences sharedPreferences,String key) {if(key.equals("CheckBox")){boolean value = sharedPreferences.getBoolean(key, false);Log.i(TAG, "CheckBox:"+value);}else if(key.equals("ListPreference")){String value = sharedPreferences.getString(key, null);Log.i(TAG, "ListPreference:"+value);}else if(key.equals("MultiSelectListPreference")){Set<String> values = sharedPreferences.getStringSet("MultiSelectListPreference", null);Log.i(TAG, "MultiSelectListPreference:"+values);}else if(key.equals("RingtonePreference")){String value = sharedPreferences.getString("RingtonePreference", null);//content://media/internal/audio/media/49Log.i(TAG, "RingtonePreference:"+value);}}
}

2) preferenceheaders.xml

preference-headers作为顶级标签，包含多个header

<?xml version="1.0" encoding="utf-8"?>
<preference-headersxmlns:android="http://schemas.android.com/apk/res/android"><headerandroid:fragment="com.qinuli.buttontest2.MyPreferenceFragment"android:title="My header"android:icon="@drawable/ic_launcher"android:summary="description of header"/><headerandroid:title="Intent"android:summary="launch an intent"><intent android:action="android.settings.DISPLAY_SETTINGS"/></header>
</preference-headers>

3) MyPreferenceFragment.java

public class MyPreferenceFragment extends PreferenceFragment {@Overridepublic void onCreate(Bundle savedInstanceState) {super.onCreate(savedInstanceState);addPreferencesFromResource(R.xml.userpreferences);}
}

4) userpreferences.xml

PreferenceScreen作为顶级标签，包含多个PreferenceCategory

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreenxmlns:android="http://schemas.android.com/apk/res/android"><PreferenceCategory android:title="Category1"><CheckBoxPreference android:key="CheckBox"android:title="CheckBox"android:summaryOn="laugh"android:summaryOff="cry"android:defaultValue="true"/><ListPreference android:key="ListPreference"android:title="ListPreference"android:summary="many things, but you can only choose one"android:entries="@array/mylist"android:entryValues="@array/myvalues"/><PreferenceScreen android:title="PreferenceScreen"android:summary="child screen"><SwitchPreference android:key="SwitchPreference"android:title="SwitchPreference"android:summaryOn="Active"android:summaryOff="Deactive"android:switchTextOn="Good"android:switchTextOff="Bad"/></PreferenceScreen></PreferenceCategory><PreferenceCategory android:title="Category2"><EditTextPreference android:key="EditText"android:title="EditText"android:summary="input something"android:defaultValue="fantastic job!"/><MultiSelectListPreference android:key="MultiSelectListPreference"android:title="MultiSelectListPreference"android:summary="you can choose as many as you want"android:entries="@array/mylist"android:entryValues="@array/myvalues"/><RingtonePreference android:key="RingtonePreference"android:title="RingtonePreference"android:summary="select your favourite ringtone"/></PreferenceCategory><PreferenceScreen android:title="Intent"android:summary="launch an intent"><intent android:action="android.settings.WIFI_SETTINGS"/></PreferenceScreen>
</PreferenceScreen>

5) strings.xml

ListPreference引用的资源

<resources><string name="app_name">ButtonTest2</string><string-array name="mylist"><item >good</item><item >great</item><item >nice</item><item >fine</item><item >beautiful</item><item >pretty</item></string-array><string-array name="myvalues"><item >_GOOD</item><item >_GREAT</item><item >_NICE</item><item >_FINE</item><item >_BEAUTIFUL</item><item >_PRETTY</item></string-array>
</resources>