기본 설정 헤더가 표시되지 않습니다.

Question

PreferenceActivity을 다시 쓰려고합니다. Preference-Headers 공식 문서를 따르지만 내 머리글이 표시되지 않습니다. 방금 빈 화면이 나타납니다.

<?xml version="1.0" encoding="utf-8"?> 
<preference-headers xmlns:android="http://schemas.android.com/apk/res/android"> 
    <preference-headers xmlns:android="http://schemas.android.com/apk/res/android"> 
     <header 
       android:fragment="com.mikebdev.refuel.SettingsActivity$DesignFragment" 
       android:title="@string/pref_header_design" 
       android:summary="@string/pref_header_design_summary" 
       /> 
     <header 
       android:fragment="com.mikebdev.refuel.SettingsActivity$SettingsFragment" 
       android:title="@string/pref_header_units" 
       android:summary="@string/pref_header_units_summary"/> 
     <header 
       android:fragment="com.mikebdev.refuel.SettingsActivity$DatabaseFragment" 
       android:title="@string/pref_header_db" 
       android:summary="@string/pref_header_db_summary"/> 
    </preference-headers> 
</preference-headers> 

그리고 heres는 내 SettingsActivity :

import android.app.AlertDialog; 
import android.content.Context; 
import android.content.DialogInterface; 
import android.os.Bundle; 
import android.os.Environment; 
import android.preference.Preference; 
import android.preference.PreferenceActivity; 
import android.preference.PreferenceFragment; 
import android.preference.PreferenceManager; 
import android.widget.Toast; 

import com.google.analytics.tracking.android.EasyTracker; 

import java.io.File; 
import java.io.FileInputStream; 
import java.io.FileNotFoundException; 
import java.io.FileOutputStream; 
import java.io.IOException; 
import java.io.InputStream; 
import java.io.OutputStream; 
import java.util.List; 

public class SettingsActivity extends PreferenceActivity { 

    public static final String PREFS_NAME = "RFPref"; 
    public static PreferenceManager prefMgr; 



    @Override 
    public void onBuildHeaders(List<Header> target) { 
     loadHeadersFromResource(R.xml.pref_headers, target); 
    } 
} 

나는 내부 PreferenceFragment 클래스를 떠나려고하고 ..

내가 뭘 잘못하고

여기 내 XML입니까?

Answer 1

<preference-headers> 개의 요소가 있습니다. 내면을 제거하십시오.