topics/ui/settings.jd

page.title=
page.tags=preference,preferenceactivity,preferencefragment

@jd:body


<div id="qv-wrapper">
<div id="qv">

<h2> </h2>
<ol>
  <li><a href="#Overview"></a>
    <ol>
      <li><a href="#SettingTypes"></a></li>
    </ol>
  </li>
  <li><a href="#DefiningPrefs">   XML</a>
    <ol>
      <li><a href="#Groups">  </a></li>
      <li><a href="#Intents"> </a></li>
    </ol>
  </li>
  <li><a href="#Activity">  </a></li>
  <li><a href="#Fragment">  </a></li>
  <li><a href="#Defaults">   </a></li>
  <li><a href="#PreferenceHeaders">  </a>
    <ol>
      <li><a href="#CreateHeaders">  </a></li>
      <li><a href="#DisplayHeaders"> </a></li>
      <li><a href="#BackCompatHeaders">     </a></li>
    </ol>
  </li>
  <li><a href="#ReadingPrefs"> </a>
    <ol>
      <li><a href="#Listening">  </a></li>
    </ol>
  </li>
  <li><a href="#NetworkUsage">  </a></li>
  <li><a href="#Custom">  </a>
    <ol>
      <li><a href="#CustomSelected">  </a></li>
      <li><a href="#CustomSave">  </a></li>
      <li><a href="#CustomInitialize">  </a></li>
      <li><a href="#CustomDefault">   </a></li>
      <li><a href="#CustomSaveState">    </a></li>
    </ol>
  </li>
</ol>

<h2> </h2>
<ol>
  <li>{@link android.preference.Preference}</li>
  <li>{@link android.preference.PreferenceActivity}</li>
  <li>{@link android.preference.PreferenceFragment}</li>
</ol>


<h2>. :</h2>
<ol>
  <li><a href="{@docRoot}design/patterns/settings.html">   </a></li>
</ol>
</div>
</div>


<p>    ,        . ,

   .</p>

<p>       ,
API- {@link android.preference.Preference}  Android   ,
     Android (  ).    ,
      API- {@link android.preference.Preference}.</p>

<div class="note design">
<p><strong> </strong></p>
  <p>     .     <a href="{@docRoot}design/patterns/settings.html"></a>.</p>
</div>


<img src="{@docRoot}images/ui/settings/settings.png" alt="" width="435" />
<p class="img-caption"><strong> 1.</strong>     Android
  .  ,   {@link android.preference.Preference},
    .</p>


<h2 id="Overview"></h2>

<p>    {@link android.view.View}    ,
     {@link android.preference.Preference},
  XML-.</p>

<p> {@link android.preference.Preference}
.   {@link android.preference.Preference}
      . , {@link
android.preference.CheckBoxPreference}   ,   ,  {@link
android.preference.ListPreference}  ,         .</p>

<p>    {@link android.preference.Preference}    -,
        {@link android.content.SharedPreferences}
     .    ,
   {@link android.content.SharedPreferences}.
   ,   {@link android.content.SharedPreferences},   ,
            .</p>

<p>,   {@link android.content.SharedPreferences}   ,
  :</p>

<ul>
  <li> </li>
  <li>   </li>
  <li> </li>
  <li>  </li>
  <li></li>
  <li> {@link java.util.Set}</li>
</ul>

<p>         {@link android.preference.Preference},

 {@link android.view.View},      {@link android.app.Activity}
{@link android.app.Fragment}     :</p>

<ul>
  <li>     Android  3.0 (API  10  ),
   {@link android.preference.PreferenceActivity}.</li>
  <li>   Android 3.0            {@link android.app.Activity},
   {@link android.preference.PreferenceFragment}     .
,       ,
 {@link android.preference.PreferenceActivity}         .</li>
</ul>

<p>  {@link android.preference.PreferenceActivity}   {@link
android.preference.PreferenceFragment}    <a href="#Activity">  </a>  <a href="#Fragment">
 </a>.</p>


<h3 id="SettingTypes"></h3>

<p>         {@link
android.preference.Preference}.      ,
, ,        .
     .      1
 Android   .          {@link
android.preference.Preference}.</p>

<p>    :</p>

<dl>
  <dt>{@link android.preference.CheckBoxPreference}</dt>
  <dd>     ,      .
   (<code>true</code>,   ).</dd>

  <dt>{@link android.preference.ListPreference}</dt>
  <dd>     .
        ( ).</dd>

  <dt>{@link android.preference.EditTextPreference}</dt>
  <dd>     {@link android.widget.EditText}.   {@link
java.lang.String}.</dd>
</dl>

<p>.  {@link android.preference.Preference},
 .</p>

<p>,      ,
-  . ,        {@link
android.preference.Preference}     .
   {@link android.preference.Preference}. .  <a href="#Custom">  </a>.</p>


<h2 id="DefiningPrefs">   XML</h2>

<p>       {@link android.preference.Preference}   ,
     XML
 {@link android.preference.Preference}.   XML      ,
  ,   .  ,
  ,          .</p>

<p>   {@link android.preference.Preference}      XML,
   , , {@code &lt;CheckBoxPreference&gt;}.</p>

<p>    XML   {@code res/xml/}.
,    {@code preferences.xml}.      ,
   (    )
 {@link android.preference.PreferenceScreen}.</p>

<p class="note"><strong>.</strong>
,     XML   .</p>

<p>  XML-    {@link android.preference.PreferenceScreen
&lt;PreferenceScreen&gt;}.        {@link
android.preference.Preference}.   ,
{@link android.preference.PreferenceScreen &lt;PreferenceScreen&gt;},
   .</p>

<p>:</p>

<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;CheckBoxPreference
        android:key="pref_sync"
        android:title="@string/pref_sync"
        android:summary="@string/pref_sync_summ"
        android:defaultValue="true" />
    &lt;ListPreference
        android:dependency="pref_sync"
        android:key="pref_syncConnectionType"
        android:title="@string/pref_syncConnectionType"
        android:dialogTitle="@string/pref_syncConnectionType"
        android:entries="@array/pref_syncConnectionTypes_entries"
        android:entryValues="@array/pref_syncConnectionTypes_values"
        android:defaultValue="@string/pref_syncConnectionTypes_default" />
&lt;/PreferenceScreen>
</pre>

<p>    {@link android.preference.CheckBoxPreference}  {@link
android.preference.ListPreference}.     :</p>

<dl>
  <dt>{@code android:key}</dt>
  <dd>    ,    .
 (),          {@link
android.content.SharedPreferences}.
  <p>  <em>  </em>
{@link android.preference.PreferenceCategory}  {@link android.preference.PreferenceScreen},
   {@link android.content.Intent}   (  <a href="#Intents">{@code &lt;intent&gt;}</a>)   {@link android.app.Fragment}   (   <a href="{@docRoot}reference/android/preference/Preference.html#attr_android:fragment">{@code
android:fragment}</a>).</p>
  </dd>
  <dt>{@code android:title}</dt>
  <dd>    ,   .</dd>
  <dt>{@code android:defaultValue}</dt>
  <dd>    ,       {@link
android.content.SharedPreferences}.
.</dd>
</dl>

<p>        .  {@link
android.preference.Preference} (  ).</p>


<div class="figure" style="width:300px">
  <img src="{@docRoot}images/ui/settings/settings-titles.png" alt="" />
  <p class="img-caption"><strong> 2.</strong>
  . <br/><b>1.</b>    {@link
android.preference.PreferenceCategory &lt;PreferenceCategory&gt;}. <br/><b>2.</b>
   {@code android:title}.</p>
</div>


<p>      10 , , ,

  .      .</p>


<h3 id="Groups">  </h3>

<p>     10   ,
    ,   .   ,
      ,
  .          :</p>

<ul>
  <li><a href="#Titles"> </a></li>
  <li><a href="#Subscreens"> </a></li>
</ul>

<p>               .
         ,
<a href="{@docRoot}design/patterns/settings.html"></a>    Android.</p>


<h4 id="Titles"> </h4>

<p>          (    2),
    {@link android.preference.Preference}  {@link
android.preference.PreferenceCategory}.</p>

<p>:</p>

<pre>
&lt;PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;PreferenceCategory
        android:title="&#64;string/pref_sms_storage_title"
        android:key="pref_key_storage_settings">
        &lt;CheckBoxPreference
            android:key="pref_key_auto_delete"
            android:summary="&#64;string/pref_summary_auto_delete"
            android:title="&#64;string/pref_title_auto_delete"
            android:defaultValue="false"... />
        &lt;Preference
            android:key="pref_key_sms_delete_limit"
            android:dependency="pref_key_auto_delete"
            android:summary="&#64;string/pref_summary_delete_limit"
            android:title="&#64;string/pref_title_sms_delete"... />
        &lt;Preference
            android:key="pref_key_mms_delete_limit"
            android:dependency="pref_key_auto_delete"
            android:summary="&#64;string/pref_summary_delete_limit"
            android:title="&#64;string/pref_title_mms_delete" ... />
    &lt;/PreferenceCategory>
    ...
&lt;/PreferenceScreen>
</pre>


<h4 id="Subscreens"> </h4>

<p>        (    3),
 {@link android.preference.Preference}  {@link
android.preference.PreferenceScreen}.</p>

<img src="{@docRoot}images/ui/settings/settings-subscreen.png" alt="" />
<p class="img-caption"><strong> 3.</strong>  .  {@code
&lt;PreferenceScreen&gt;}
 ,        .</p>

<p>:</p>

<pre>
&lt;PreferenceScreen  xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;!-- opens a subscreen of settings -->
    &lt;PreferenceScreen
        android:key="button_voicemail_category_key"
        android:title="&#64;string/voicemail"
        android:persistent="false">
        &lt;ListPreference
            android:key="button_voicemail_provider_key"
            android:title="&#64;string/voicemail_provider" ... />
        &lt;!-- opens another nested subscreen -->
        &lt;PreferenceScreen
            android:key="button_voicemail_setting_key"
            android:title="&#64;string/voicemail_settings"
            android:persistent="false">
            ...
        &lt;/PreferenceScreen>
        &lt;RingtonePreference
            android:key="button_voicemail_ringtone_key"
            android:title="&#64;string/voicemail_ringtone_title"
            android:ringtoneType="notification" ... />
        ...
    &lt;/PreferenceScreen>
    ...
&lt;/PreferenceScreen>
</pre>


<h3 id="Intents"> </h3>

<p>    ,      ,
 , , -   -.   {@link
android.content.Intent},     ,   {@code &lt;intent&gt;}
      {@code &lt;Preference&gt;}.</p>

<p>,        -:</p>

<pre>
&lt;Preference android:title="@string/prefs_web_page" >
    &lt;intent android:action="android.intent.action.VIEW"
            android:data="http://www.example.com" />
&lt;/Preference>
</pre>

<p>          :</p>

<dl>
  <dt>{@code android:action}</dt>
    <dd> ,
  {@link android.content.Intent#setAction setAction()}.</dd>
  <dt>{@code android:data}</dt>
    <dd> ,    {@link android.content.Intent#setData setData()}.</dd>
  <dt>{@code android:mimeType}</dt>
    <dd>  MIME,
  {@link android.content.Intent#setType setType()}.</dd>
  <dt>{@code android:targetClass}</dt>
    <dd>  ,  ,    {@link android.content.Intent#setComponent
setComponent()}.</dd>
  <dt>{@code android:targetPackage}</dt>
    <dd>   ,    {@link
android.content.Intent#setComponent setComponent()}.</dd>
</dl>


<h2 id="Activity">  </h2>

<p>        {@link
android.preference.PreferenceActivity}.     {@link
android.app.Activity},         {@link
android.preference.Preference}. {@link android.preference.PreferenceActivity}
  ,     {@link
android.preference.Preference},    .</p>

<p class="note"><strong>.</strong>      Android 3.0
      {@link android.preference.PreferenceFragment}.
<a href="#Fragment">  </a>.</p>

<p>  :          {@link
android.preference.PreferenceActivity#onCreate onCreate()}.    {@link
android.preference.PreferenceActivity#addPreferencesFromResource addPreferencesFromResource()}
 ,   XML-  . ,
  ,    {@link android.preference.PreferenceActivity}:</p>

<pre>
public class SettingsActivity extends PreferenceActivity {
    &#64;Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        addPreferencesFromResource(R.xml.preferences);
    }
}
</pre>

<p>      ,      ,
     {@link android.content.SharedPreferences}  ,
     ,     .
   ,   ,   .
      {@link android.content.SharedPreferences}
.   <a href="#ReadingPrefs"> </a>.</p>


<h2 id="Fragment">  </h2>

<p>    Android 3.0 (API  11)       {@link
android.preference.PreferenceFragment}
 {@link android.preference.Preference}.    {@link android.preference.PreferenceFragment}   ,
  {@link android.preference.PreferenceActivity}.</p>

<p><a href="{@docRoot}guide/components/fragments.html"></a>
          ,
 . ,          {@link
android.preference.PreferenceFragment}  {@link
android.preference.PreferenceActivity}   .</p>

<p>  {@link android.preference.PreferenceFragment}
  {@link android.preference.PreferenceFragment#onCreate onCreate()}
   {@link android.preference.PreferenceFragment#addPreferencesFromResource
addPreferencesFromResource()}. :</p>

<pre>
public static class SettingsFragment extends PreferenceFragment {
    &#64;Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Load the preferences from an XML resource
        addPreferencesFromResource(R.xml.preferences);
    }
    ...
}
</pre>

<p>        {@link android.app.Activity},
{@link android.app.Fragment}. :</p>

<pre>
public class SettingsActivity extends Activity {
    &#64;Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Display the fragment as the main content.
        getFragmentManager().beginTransaction()
                .replace(android.R.id.content, new SettingsFragment())
                .commit();
    }
}
</pre>

<p class="note"><strong>.</strong>  {@link android.preference.PreferenceFragment}
  {@link android.content.Context}.     {@link android.content.Context},
  {@link android.app.Fragment#getActivity()}.
{@link android.app.Fragment#getActivity()}    ,     .
           ,  {@link
android.app.Fragment#getActivity()}  null.</p>


<h2 id="Defaults">   </h2>

<p>,        ,
    {@link android.content.SharedPreferences},
         {@link android.preference.Preference}
 .</p>

<p>           {@link
android.preference.Preference}
  XML-   {@code android:defaultValue}.
 ,     {@link android.preference.Preference}. :
</p>

<pre>
&lt;!-- default value is a boolean -->
&lt;CheckBoxPreference
    android:defaultValue="true"
    ... />

&lt;!-- default value is a string -->
&lt;ListPreference
    android:defaultValue="@string/pref_syncConnectionTypes_default"
    ... />
</pre>

<p>   {@link android.app.Activity#onCreate onCreate()}
(    ,
  )  {@link android.preference.PreferenceManager#setDefaultValues
setDefaultValues()}:</p>

<pre>
PreferenceManager.setDefaultValues(this, R.xml.advanced_preferences, false);
</pre>

<p>     {@link android.app.Activity#onCreate onCreate()} ,
       ,
   (,
  ).</p>

<p>    :</p>
<ul>
  <li>{@link android.content.Context}  .</li>
  <li>   XML- ,        .</li>
  <li> ,  ,         .
<p>  <code>false</code>         ,
(  {@link android.preference.PreferenceManager#KEY_HAS_SET_DEFAULT_VALUES}
        false).</p></li>
</ul>

<p>      <code>false</code>,
   ,       -
 . ,       <code>true</code>,
   .</p>


<h2 id="PreferenceHeaders">  </h2>

<p>       ,
 <a href="#Subscreens"></a> (,     ,
   4  5).      Android 3.0
   Android 3.0 ,
 {@link android.preference.PreferenceScreen}.</p>

<p>    ,   :</p>
<ol>
  <li>       {@link
android.preference.PreferenceFragment}.  ,
XML-.</li>
  <li> XML- ,        ,
   .</li>
  <li>  {@link android.preference.PreferenceActivity},     .</li>
  <li>   {@link
android.preference.PreferenceActivity#onBuildHeaders onBuildHeaders()},
 .</li>
</ol>

<p>       ,       {@link android.preference.PreferenceActivity}
     ,    4.</p>

<p>      Android  3.0,
,  {@link android.preference.PreferenceFragment}

 (.  <a href="#BackCompatHeaders">
 </a>).</p>

<img src="{@docRoot}images/ui/settings/settings-headers-tablet.png" alt="" />
<p class="img-caption"><strong>4.</strong>    . <br/><b>1.</b>
  XML- . <br/><b>2.</b>
{@link android.preference.PreferenceFragment},    {@code &lt;header&gt;}
  .</p>

<img src="{@docRoot}images/ui/settings/settings-headers-handset.png" alt="" />
<p class="img-caption"><strong>5.</strong>    .

 {@link android.preference.PreferenceFragment}.</p>


<h3 id="CreateHeaders" style="clear:left">  </h3>

<p>          {@code &lt;header&gt;}
   {@code &lt;preference-headers&gt;}. :</p>

<pre>
&lt;?xml version="1.0" encoding="utf-8"?>
&lt;preference-headers xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;header
        android:fragment="com.example.prefs.SettingsActivity$SettingsFragmentOne"
        android:title="@string/prefs_category_one"
        android:summary="@string/prefs_summ_category_one" />
    &lt;header
        android:fragment="com.example.prefs.SettingsActivity$SettingsFragmentTwo"
        android:title="@string/prefs_category_two"
        android:summary="@string/prefs_summ_category_two" >
        &lt;!-- key/value pairs can be included as arguments for the fragment. -->
        &lt;extra android:name="someKey" android:value="someHeaderValue" />
    &lt;/header>
&lt;/preference-headers>
</pre>

<p>  {@code android:fragment}      {@link
android.preference.PreferenceFragment},        .</p>

<p> {@code &lt;extras&gt;}    -    {@link
android.os.Bundle}.        {@link
android.app.Fragment#getArguments()}.        ,
           {@link
android.preference.PreferenceFragment}
XML- ,     .</p>

<p>,   ,        ,
   {@code &lt;extra&gt;}   {@code "settings"}:</p>

<pre>
public static class SettingsFragment extends PreferenceFragment {
    &#64;Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        String settings = getArguments().getString("settings");
        if ("notifications".equals(settings)) {
            addPreferencesFromResource(R.xml.settings_wifi);
        } else if ("sync".equals(settings)) {
            addPreferencesFromResource(R.xml.settings_sync);
        }
    }
}
</pre>


<h3 id="DisplayHeaders"> </h3>

<p>   ,       {@link
android.preference.PreferenceActivity#onBuildHeaders onBuildHeaders()}
{@link android.preference.PreferenceActivity#loadHeadersFromResource
loadHeadersFromResource()}. :</p>

<pre>
public class SettingsActivity extends PreferenceActivity {
    &#64;Override
    public void onBuildHeaders(List&lt;Header> target) {
        loadHeadersFromResource(R.xml.preference_headers, target);
    }
}
</pre>

<p>      ,    {@link
android.preference.PreferenceFragment}.</p>

<p class="note"><strong>.</strong>       {@link
android.preference.PreferenceActivity}     {@link
android.preference.PreferenceActivity#onCreate onCreate()},
   .</p>


<h3 id="BackCompatHeaders">     </h3>

<p>     Android  3.0,
      Android 3.0    .
 XML- ,    {@link android.preference.Preference
&lt;Preference&gt;},       (
Android).</p>

<p>    {@link android.preference.PreferenceScreen}    {@link
android.preference.Preference &lt;Preference&gt;}   {@link android.content.Intent}
{@link android.preference.PreferenceActivity}   XML-
 .</p>

<p>    XML-   ,    Android  3.0
    ({@code res/xml/preference_headers.xml}):</p>

<pre>
&lt;preference-headers xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;header
        android:fragment="com.example.prefs.SettingsFragmentOne"
        android:title="@string/prefs_category_one"
        android:summary="@string/prefs_summ_category_one" />
    &lt;header
        android:fragment="com.example.prefs.SettingsFragmentTwo"
        android:title="@string/prefs_category_two"
        android:summary="@string/prefs_summ_category_two" />
&lt;/preference-headers>
</pre>

<p>    ,
Android 3.0 ({@code res/xml/preference_headers_legacy.xml}):</p>

<pre>
&lt;PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android">
    &lt;Preference
        android:title="@string/prefs_category_one"
        android:summary="@string/prefs_summ_category_one"  >
        &lt;intent
            android:targetPackage="com.example.prefs"
            android:targetClass="com.example.prefs.SettingsActivity"
            android:action="com.example.prefs.PREFS_ONE" />
    &lt;/Preference>
    &lt;Preference
        android:title="@string/prefs_category_two"
        android:summary="@string/prefs_summ_category_two" >
        &lt;intent
            android:targetPackage="com.example.prefs"
            android:targetClass="com.example.prefs.SettingsActivity"
            android:action="com.example.prefs.PREFS_TWO" />
    &lt;/Preference>
&lt;/PreferenceScreen>
</pre>

<p>   {@code &lt;preference-headers&gt;}     Android 3.0,
{@link android.preference.PreferenceActivity#onBuildHeaders onBuildHeaders()}   {@link
android.preference.PreferenceActivity}     Android  3.0    .
   ({@code preference_headers_legacy.xml}),     Android
,    Android 3.0 ({@link
android.os.Build.VERSION_CODES#HONEYCOMB}),  {@link
android.preference.PreferenceActivity#addPreferencesFromResource addPreferencesFromResource()}
   . :</p>

<pre>
&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    ...

    if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.HONEYCOMB) {
        // Load the legacy preferences headers
        addPreferencesFromResource(R.xml.preference_headers_legacy);
    }
}

// Called only on Honeycomb and later
&#64;Override
public void onBuildHeaders(List&lt;Header> target) {
   loadHeadersFromResource(R.xml.preference_headers, target);
}
</pre>

<p>   {@link android.content.Intent},
 ,      .
   ,      {@code &lt;intent&gt;} XML- :</p>

<pre>
final static String ACTION_PREFS_ONE = "com.example.prefs.PREFS_ONE";
...

&#64;Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    String action = getIntent().getAction();
    if (action != null &amp;&amp; action.equals(ACTION_PREFS_ONE)) {
        addPreferencesFromResource(R.xml.preferences);
    }
    ...

    else if (Build.VERSION.SDK_INT &lt; Build.VERSION_CODES.HONEYCOMB) {
        // Load the legacy preferences headers
        addPreferencesFromResource(R.xml.preference_headers_legacy);
    }
}
</pre>

<p>  ,    {@link
android.preference.PreferenceActivity#addPreferencesFromResource addPreferencesFromResource()}
    ,     else-if,
     .</p>


<h2 id="ReadingPrefs"> </h2>

<p>        ,
      {@link
android.preference.PreferenceManager#getDefaultSharedPreferences
PreferenceManager.getDefaultSharedPreferences()}.    {@link
android.content.SharedPreferences},    -,
  {@link android.preference.Preference},     {@link
android.preference.PreferenceActivity}.</p>

<p>
:</p>

<pre>
SharedPreferences sharedPref = PreferenceManager.getDefaultSharedPreferences(this);
String syncConnPref = sharedPref.getString(SettingsActivity.KEY_PREF_SYNC_CONN, "");
</pre>


<h3 id="Listening">  </h3>

<p>  ,       ,
.         ,
  {@link android.content.SharedPreferences.OnSharedPreferenceChangeListener
SharedPreference.OnSharedPreferenceChangeListener}
{@link android.content.SharedPreferences}   {@link
android.content.SharedPreferences#registerOnSharedPreferenceChangeListener
registerOnSharedPreferenceChangeListener()}.</p>

<p>       , {@link
android.content.SharedPreferences.OnSharedPreferenceChangeListener#onSharedPreferenceChanged
onSharedPreferenceChanged()},  , ,
. :</p>

<pre>
public class SettingsActivity extends PreferenceActivity
                              implements OnSharedPreferenceChangeListener {
    public static final String KEY_PREF_SYNC_CONN = "pref_syncConnectionType";
    ...

    public void onSharedPreferenceChanged(SharedPreferences sharedPreferences,
        String key) {
        if (key.equals(KEY_PREF_SYNC_CONN)) {
            Preference connectionPref = findPreference(key);
            // Set summary to be the user-description for the selected value
            connectionPref.setSummary(sharedPreferences.getString(key, ""));
        }
    }
}
</pre>

<p>    ,        .
 {@link android.preference.PreferenceActivity#findPreference findPreference()}
{@link android.preference.Preference},   ,
,   .  ,     {@link
android.preference.ListPreference}       ,        {@link
android.preference.Preference#setSummary setSummary()}
  (,   ,    5).</p>

<p class="note"><strong>.</strong>      <a href="{@docRoot}design/patterns/settings.html"></a>    Android,
  {@link android.preference.ListPreference}     ,
   .</p>

<p>
  {@link android.content.SharedPreferences.OnSharedPreferenceChangeListener}      {@link
android.app.Activity#onResume}  {@link android.app.Activity#onPause} :</p>

<pre>
&#64;Override
protected void onResume() {
    super.onResume();
    getPreferenceScreen().getSharedPreferences()
            .registerOnSharedPreferenceChangeListener(this);
}

&#64;Override
protected void onPause() {
    super.onPause();
    getPreferenceScreen().getSharedPreferences()
            .unregisterOnSharedPreferenceChangeListener(this);
}
</pre>

<p class="caution"><strong>!</strong>     {@link
android.content.SharedPreferences#registerOnSharedPreferenceChangeListener
registerOnSharedPreferenceChangeListener()},
    .
  ,         .

,   ,    .</p>

<p>,
  .
      :</p>

<pre>
prefs.registerOnSharedPreferenceChangeListener(
  // Bad! The listener is subject to garbage collection!
  new SharedPreferences.OnSharedPreferenceChangeListener() {
  public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    // listener implementation
  }
});
</pre>

<p>
,   ,   :</p>

<pre>
SharedPreferences.OnSharedPreferenceChangeListener listener =
    new SharedPreferences.OnSharedPreferenceChangeListener() {
  public void onSharedPreferenceChanged(SharedPreferences prefs, String key) {
    // listener implementation
  }
};
prefs.registerOnSharedPreferenceChangeListener(listener);
</pre>

<h2 id="NetworkUsage">  </h2>


<p>   Android 4.0,
  ,        .
        .  ,
  ,
         .<p>

<p>,         ,
     Wi-Fi,      ..
   ,          ,
       ,
   ,    .</p>

<p>       {@link android.preference.PreferenceActivity}
              {@link
android.content.Intent#ACTION_MANAGE_NETWORK_USAGE}    . :</p>

<pre>
&lt;activity android:name="SettingsActivity" ... >
    &lt;intent-filter>
       &lt;action android:name="android.intent.action.MANAGE_NETWORK_USAGE" />
       &lt;category android:name="android.intent.category.DEFAULT" />
    &lt;/intent-filter>
&lt;/activity>
</pre>

<p>    ,
  . ,
,   <em>  </em>,
{@link android.preference.PreferenceActivity},    ,
 .</p>


<h2 id="Custom">  </h2>

<p> Android    {@link android.preference.Preference},
         .
  ,   ,        , ,
  .
 {@link android.preference.Preference}     .</p>

<p>   {@link android.preference.Preference}
 :</p>

<ul>
  <li>  ,        .</li>
  <li>    .</li>
  <li> {@link android.preference.Preference}   (   ),
  .</li>
  <li>        .</li>
  <li> {@link android.preference.Preference}      (,  ),
        (,    ).</li>
</ul>

<p>        .</p>


<h3 id="CustomSelected">  </h3>

  <p>    {@link android.preference.Preference} ,
{@link android.preference.Preference#onClick()},   ,
 .       {@link android.preference.DialogPreference},
  ,   .    {@link
android.preference.DialogPreference},    {@link
android.preference.DialogPreference#setDialogLayoutResource setDialogLayoutResourcs()},
,     .</p>

  <p>        {@link
android.preference.DialogPreference},
      :</p>

<pre>
public class NumberPickerPreference extends DialogPreference {
    public NumberPickerPreference(Context context, AttributeSet attrs) {
        super(context, attrs);

        setDialogLayoutResource(R.layout.numberpicker_dialog);
        setPositiveButtonText(android.R.string.ok);
        setNegativeButtonText(android.R.string.cancel);

        setDialogIcon(null);
    }
    ...
}
</pre>


<h3 id="CustomSave">  </h3>

<p>       ,     {@code persist*()}  {@link
android.preference.Preference}, , {@link
android.preference.Preference#persistInt persistInt()},     ,
{@link android.preference.Preference#persistBoolean persistBoolean()}    .</p>

<p class="note"><strong>.</strong>   {@link android.preference.Preference}
 ,      {@code persist*()},   ,
  {@link android.preference.Preference}.</p>

<p>         {@link
android.preference.Preference}.    {@link
android.preference.DialogPreference},
   (   OK).</p>

<p> {@link android.preference.DialogPreference} ,    {@link
android.preference.DialogPreference#onDialogClosed onDialogClosed()}.
 ,  ,
<code>true</code>,           . :
</p>

<pre>
&#64;Override
protected void onDialogClosed(boolean positiveResult) {
    // When the user selects "OK", persist the new value
    if (positiveResult) {
        persistInt(mNewValue);
    }
}
</pre>

<p>   <code>mNewValue</code>    ,
.   {@link android.preference.Preference#persistInt persistInt()}
  {@link android.content.SharedPreferences} (   ,
  XML-    {@link android.preference.Preference}).</p>


<h3 id="CustomInitialize">  </h3>

<p>     {@link android.preference.Preference}  ,
  {@link android.preference.Preference#onSetInitialValue onSetInitialValue()},   ,
    .    ,
  .</p>

<p> {@link android.preference.Preference#onSetInitialValue onSetInitialValue()}
 , <code>restorePersistedValue</code>,  ,
 .    <code>true</code>,     ,
   {@code getPersisted*()}  {@link
android.preference.Preference}, , {@link
android.preference.Preference#getPersistedInt getPersistedInt()}   .
   ,
  .</p>

<p> <code>restorePersistedValue</code>   <code>false</code>,
    ,     .</p>

<pre>
&#64;Override
protected void onSetInitialValue(boolean restorePersistedValue, Object defaultValue) {
    if (restorePersistedValue) {
        // Restore existing state
        mCurrentValue = this.getPersistedInt(DEFAULT_VALUE);
    } else {
        // Set default state from the XML attribute
        mCurrentValue = (Integer) defaultValue;
        persistInt(mCurrentValue);
    }
}
</pre>

<p>  {@code getPersisted*()}  ,
    ,     ,    .
            ,  {@link
android.preference.Preference#getPersistedInt getPersistedInt()}     .</p>

<p class="caution"><strong>!</strong>  <strong> </strong>
<code>defaultValue</code>        {@code getPersisted*()},
    null,  <code>restorePersistedValue</code>   <code>true</code>.</p>


<h3 id="CustomDefault">   </h3>

<p>    {@link android.preference.Preference}
(   {@code android:defaultValue}),
  {@link android.preference.Preference#onGetDefaultValue
onGetDefaultValue()},        .
 ,         {@link
android.content.SharedPreferences}. :</p>

<pre>
&#64;Override
protected Object onGetDefaultValue(TypedArray a, int index) {
    return a.getInteger(index, DEFAULT_VALUE);
}
</pre>

<p>    :
 {@code android:defaultValue},    . ,
  ,       ,   ,
       ,    .</p>


<h3 id="CustomSaveState">    </h3>

<p>  {@link android.view.View}  ,   {@link android.preference.Preference}

(,    ).
   {@link android.preference.Preference},
     {@link android.preference.Preference#onSaveInstanceState
onSaveInstanceState()}  {@link
android.preference.Preference#onRestoreInstanceState onRestoreInstanceState()}.</p>

<p>  {@link android.preference.Preference}  ,
 {@link android.os.Parcelable}.  Android
        :  {@link
android.preference.Preference.BaseSavedState}.</p>

<p> ,    {@link android.preference.Preference}   ,
  {@link android.preference.Preference.BaseSavedState}.

{@link android.preference.Preference.BaseSavedState#CREATOR}.</p>

<p>           ,
 {@code value},    {@link android.preference.Preference}
,   .</p>

<pre>
private static class SavedState extends BaseSavedState {
    // Member that holds the setting's value
    // Change this data type to match the type saved by your Preference
    int value;

    public SavedState(Parcelable superState) {
        super(superState);
    }

    public SavedState(Parcel source) {
        super(source);
        // Get the current preference's value
        value = source.readInt();  // Change this to read the appropriate data type
    }

    &#64;Override
    public void writeToParcel(Parcel dest, int flags) {
        super.writeToParcel(dest, flags);
        // Write the preference's value
        dest.writeInt(value);  // Change this to write the appropriate data type
    }

    // Standard creator object using an instance of this class
    public static final Parcelable.Creator&lt;SavedState> CREATOR =
            new Parcelable.Creator&lt;SavedState>() {

        public SavedState createFromParcel(Parcel in) {
            return new SavedState(in);
        }

        public SavedState[] newArray(int size) {
            return new SavedState[size];
        }
    };
}
</pre>

<p>     {@link android.preference.Preference.BaseSavedState}
   (      {@link android.preference.Preference}),
   {@link android.preference.Preference#onSaveInstanceState
onSaveInstanceState()}  {@link
android.preference.Preference#onRestoreInstanceState onRestoreInstanceState()}
 {@link android.preference.Preference}.</p>

<p>:</p>

<pre>
&#64;Override
protected Parcelable onSaveInstanceState() {
    final Parcelable superState = super.onSaveInstanceState();
    // Check whether this Preference is persistent (continually saved)
    if (isPersistent()) {
        // No need to save instance state since it's persistent,
        // use superclass state
        return superState;
    }

    // Create instance of custom BaseSavedState
    final SavedState myState = new SavedState(superState);
    // Set the state's value with the class member that holds current
    // setting value
    myState.value = mNewValue;
    return myState;
}

&#64;Override
protected void onRestoreInstanceState(Parcelable state) {
    // Check whether we saved the state in onSaveInstanceState
    if (state == null || !state.getClass().equals(SavedState.class)) {
        // Didn't save the state, so call superclass
        super.onRestoreInstanceState(state);
        return;
    }

    // Cast state to custom BaseSavedState and pass to superclass
    SavedState myState = (SavedState) state;
    super.onRestoreInstanceState(myState.getSuperState());

    // Set this Preference's widget to reflect the restored state
    mNumberPicker.setValue(myState.value);
}
</pre>