PreferenceActivity的使用

事实上，PreferenceActivity是继承自ListActivity，如下：

public abstract class PreferenceActivity extends ListActivity implements PreferenceFragment.OnPreferenceStartFragmentCallback

下面是一个简单的PreferenceActivity的例子：

public class PreferenceWithHeaders extends PreferenceActivity {
    @Override
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);

        // Add a button to the header list.
        if (hasHeaders()) {
            Button button = new Button(this);
            button.setText("Some action");
            setListFooter(button);
        }
    }

    /**
     * Populate the activity with the top-level headers.
     */
    @Override
    public void onBuildHeaders(List<Header> target) {
        loadHeadersFromResource(R.xml.preference_headers, target);
    }

    /**
     * This fragment shows the preferences for the first header.
     */
    public static class Prefs1Fragment extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // Make sure default values are applied.  In a real app, you would
            // want this in a shared function that is used to retrieve the
            // SharedPreferences wherever they are needed.
            PreferenceManager.setDefaultValues(getActivity(),
                    R.xml.advanced_preferences, false);

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

    /**
     * This fragment contains a second-level set of preference that you
     * can get to by tapping an item in the first preferences fragment.
     */
    public static class Prefs1FragmentInner extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // Can retrieve arguments from preference XML.
            Log.i("args", "Arguments: " + getArguments());

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

    /**
     * This fragment shows the preferences for the second header.
     */
    public static class Prefs2Fragment extends PreferenceFragment {
        @Override
        public void onCreate(Bundle savedInstanceState) {
            super.onCreate(savedInstanceState);

            // Can retrieve arguments from headers XML.
            Log.i("args", "Arguments: " + getArguments());

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

preference_headers.xml定义如下：

<preference-headers
        xmlns:android="http://schemas.android.com/apk/res/android">

    <header android:fragment="com.example.android.apis.preference.PreferenceWithHeaders$Prefs1Fragment"
            android:icon="@drawable/ic_settings_applications"
            android:title="Prefs 1"
            android:summary="An example of some preferences." />

    <header android:fragment="com.example.android.apis.preference.PreferenceWithHeaders$Prefs2Fragment"
            android:icon="@drawable/ic_settings_display"
            android:title="Prefs 2"
            android:summary="Some other preferences you can see.">
        <!-- Arbitrary key/value pairs can be included with a header as
             arguments to its fragment. -->
        <extra android:name="someKey" android:value="someHeaderValue" />
    </header>

    <header android:icon="@drawable/ic_settings_display"
            android:title="Intent"
            android:summary="Launches an Intent.">
        <intent android:action="android.intent.action.VIEW"
                android:data="http://www.android.com" />
    </header>

</preference-headers>

Prefs1Fragment的资源文件fragmented_preferences.xml定义如下：

<PreferenceScreen
        xmlns:android="http://schemas.android.com/apk/res/android">

    <PreferenceCategory
            android:title="@string/inline_preferences">

        <CheckBoxPreference
                android:key="checkbox_preference"
                android:title="@string/title_checkbox_preference"
                android:summary="@string/summary_checkbox_preference" />

    </PreferenceCategory>

    <PreferenceCategory
            android:title="@string/dialog_based_preferences">

        <EditTextPreference
                android:key="edittext_preference"
                android:title="@string/title_edittext_preference"
                android:summary="@string/summary_edittext_preference"
                android:dialogTitle="@string/dialog_title_edittext_preference" />

        <ListPreference
                android:key="list_preference"
                android:title="@string/title_list_preference"
                android:summary="@string/summary_list_preference"
                android:entries="@array/entries_list_preference"
                android:entryValues="@array/entryvalues_list_preference"
                android:dialogTitle="@string/dialog_title_list_preference" />

    </PreferenceCategory>

    <PreferenceCategory
            android:title="@string/launch_preferences">

        <!-- This PreferenceScreen tag sends the user to a new fragment of
             preferences.  If running in a large screen, they can be embedded
             inside of the overall preferences UI. -->
        <PreferenceScreen
                android:fragment="com.example.android.apis.preference.PreferenceWithHeaders$Prefs1FragmentInner"
                android:title="@string/title_fragment_preference"
                android:summary="@string/summary_fragment_preference">
            <!-- Arbitrary key/value pairs can be included for fragment arguments -->
            <extra android:name="someKey" android:value="somePrefValue" />
        </PreferenceScreen>

        <!-- This PreferenceScreen tag sends the user to a completely different
             activity, switching out of the current preferences UI. -->
        <PreferenceScreen
                android:title="@string/title_intent_preference"
                android:summary="@string/summary_intent_preference">

            <intent android:action="android.intent.action.VIEW"
                    android:data="http://www.android.com" />

        </PreferenceScreen>

    </PreferenceCategory>

    <PreferenceCategory
            android:title="@string/preference_attributes">

        <CheckBoxPreference
                android:key="parent_checkbox_preference"
                android:title="@string/title_parent_preference"
                android:summary="@string/summary_parent_preference" />

        <!-- The visual style of a child is defined by this styled theme attribute. -->
        <CheckBoxPreference
                android:key="child_checkbox_preference"
                android:dependency="parent_checkbox_preference"
                android:layout="?android:attr/preferenceLayoutChild"
                android:title="@string/title_child_preference"
                android:summary="@string/summary_child_preference" />

    </PreferenceCategory>

</PreferenceScreen>

Prefs2Fragment和Prefs1FragmentInner的资源文件类似Prefs1Fragment资源文件的定义。

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这里是分割线

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以上是关于google的官方代码（地址在这里：https://developer.android.com/reference/android/preference/PreferenceActivity.html）
但是我运行后会报错，提示我实现isValidFragment(String fragmentName)方法，我实现这个方法并且返回true之后，就不再报错了。