Android设置Settings实现：PreferenceActivity【1】

Android设置Settings实现：PreferenceActivity【1】

Android的设置Settings功能比较常见，通常可以考虑使用PreferenceActivity实现。

PreferenceActivity需要从res/xml加载（addPreferencesFromResource）一个定义好的Preference的xml文件。比如preferences.xml：

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 <?xml version="1.0" encoding="utf-8"?>
 <PreferenceScreen xmlns:android="http://schemas.android.com/apk/res/android" >

     <PreferenceCategory android:title="【第1组】" >
         <ListPreference
             android:dialogTitle="list dialog title"
             android:entries="@array/citys"
             android:entryValues="@array/citys"
             android:key="list_key"
             android:summary="list summary"
             android:title="list title" />
     </PreferenceCategory>
     <PreferenceCategory android:title="【第2组】" >
         <EditTextPreference
             android:defaultValue="缺省值1"
             android:key="edit_text_key_1"
             android:summary="edit summary"
             android:title="edit text 1" />

         <CheckBoxPreference
             android:defaultValue="true"
             android:key="checkbox_key"
             android:summary="checkbox summary"
             android:title="checkbox title" />
     </PreferenceCategory>

     <!-- 点击将浏览和打开网页 -->
     <Preference
         android:summary="http://blog.csdn.net/zhangphil"
         android:title="浏览网页" >
         <intent
             android:action="android.intent.action.VIEW"
             android:data="http://blog.csdn.net/zhangphil" />
     </Preference>

     <!-- 此处将跳转到下一屏设置 -->
     <PreferenceScreen
         android:key="preference_screen_2_key"
         android:persistent="false"
         android:title="PreferenceScreen 2" >
         <EditTextPreference
             android:defaultValue="缺省值2"
             android:key="edit_text_key_2"
             android:summary="edit summary"
             android:title="edit text 2" />
     </PreferenceScreen>

 </PreferenceScreen>

其中需要的数组资源citys在res/values中的arrays.xml中定义好：

 <?xml version="1.0" encoding="utf-8"?>
 <resources>
     <string-array name="citys">
         <item>成都</item>
         <item>北京</item>
         <item>上海</item>
     </string-array>

 </resources>

上层Java代码：

 package zhangphil.settings;

 import android.content.SharedPreferences;
 import android.content.SharedPreferences.OnSharedPreferenceChangeListener;
 import android.os.Bundle;
 import android.preference.PreferenceActivity;
 import android.preference.PreferenceManager;
 import android.util.Log;
 import android.widget.Toast;

 public class MainActivity extends PreferenceActivity {

     private MyOnSharedPreferenceChangeListener mOnSharedPreferenceChangeListener = new MyOnSharedPreferenceChangeListener();

     @Override
     protected void onCreate(Bundle savedInstanceState) {
         super.onCreate(savedInstanceState);

         // 通用的读取设置的某个值的方法
         SharedPreferences sharedPreferences = PreferenceManager.getDefaultSharedPreferences(this);
         String s = sharedPreferences.getString("edit_text_key_2", "暂时为空");
         Log.d("edit_text_key_2", s);

         // 添加设置的选项
         addPreferencesFromResource(R.xml.preferences);

         // 注册添加设置的项数据发生变化时候的监听
         sharedPreferences.registerOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
     }

     @Override
     protected void onResume() {
         super.onResume();
         getPreferenceScreen().getSharedPreferences()
                 .registerOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
     }

     @Override
     protected void onPause() {
         super.onPause();
         getPreferenceScreen().getSharedPreferences()
                 .unregisterOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
     }

     private class MyOnSharedPreferenceChangeListener implements OnSharedPreferenceChangeListener {

         @Override
         public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
             Toast.makeText(getApplication(), key, Toast.LENGTH_SHORT).show();
         }
     }
 }