Android设置Settings：ListPreference【3】

ゝ一世哀愁。 2024-02-17 16:34 13阅读 0赞

**Android设置Settings：ListPreference【3】**

Android的Settings实现中，ListPreference使用稍微复杂些，ListPreference使用两个数据源：entries和entryValues，entries和entryValues存在对应关系，可以这么简单理解，entries是人类可读的有意义的内容，而entryValues则是用来为机器或代码使用的具体的值，在前面文章【1】和【2】的基础写一个ListPreference的使用加以说明。  
res/xml目录下的preferences.xml(有变化):

<?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_code"
                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>
    
        
        <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>
    
        
        <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>

需要的res/values/arrays.xml（注意变化）:

<?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>
        
         <string-array name="citys_code">
            <item>028</item>
            <item>010</item>
            <item>021</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.EditTextPreference;
    import android.preference.ListPreference;
    import android.preference.Preference;
    import android.preference.PreferenceActivity;
    import android.preference.PreferenceManager;
    import android.preference.PreferenceScreen;
    
    public class MainActivity extends PreferenceActivity {
    
    	private MyOnSharedPreferenceChangeListener mOnSharedPreferenceChangeListener = new MyOnSharedPreferenceChangeListener();
    
    	private EditTextPreference mEditTextPreference;
    	private final String A_KEY = "edit_text_key_1";
    
    	private ListPreference mListPreference;
    	private final String LIST_KEY = "list_key";
    
    	@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(A_KEY, "暂时为空");
    
    		// 添加设置的选项
    		addPreferencesFromResource(R.xml.preferences);
    
    		// 预读取。为PreferenceActivity中的某个设置选项初始化值
    		mEditTextPreference = (EditTextPreference) findPreference(A_KEY);
    		mEditTextPreference.setSummary(s);
    
    		// 注册添加设置的项数据发生变化时候的监听
    		sharedPreferences.registerOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
    
    		mListPreference = (ListPreference) findPreference(LIST_KEY);
    	}
    
    	@Override
    	protected void onResume() {
    		super.onResume();
    		getPreferenceScreen().getSharedPreferences()
    				.registerOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
    	}
    
    	@Override
    	protected void onPause() {
    		super.onPause();
    		getPreferenceScreen().getSharedPreferences()
    				.unregisterOnSharedPreferenceChangeListener(mOnSharedPreferenceChangeListener);
    	}
    
    	// 那一个设置选项栏被触发
    	@Override
    	public boolean onPreferenceTreeClick(PreferenceScreen preferenceScreen, Preference preference) {
    		return false;
    	}
    
    	private class MyOnSharedPreferenceChangeListener implements OnSharedPreferenceChangeListener {
    
    		@Override
    		public void onSharedPreferenceChanged(SharedPreferences sharedPreferences, String key) {
    			if (key.equals(A_KEY)) {
    				// 更新
    				String s = sharedPreferences.getString(A_KEY, "NULL");
    				mEditTextPreference.setSummary(s);
    			}
    
    			if (key.equals(LIST_KEY)) {
    				String e = mListPreference.getEntry() + "";
    				String v = mListPreference.getValue();
    				mListPreference.setSummary(e + " : " + v);
    			}
    		}
    	}
    }

运行结果：

![Center][]

相关文章和文档：  
【1】《Android设置Settings实现：PreferenceActivity【1】》链接地址：[http://blog.csdn.net/zhangphil/article/details/50154513][http_blog.csdn.net_zhangphil_article_details_50154513]  
【2】《Android设置Settings：预读取设置的选项和更新设置结果【2】》链接地址：[http://blog.csdn.net/zhangphil/article/details/50154707][http_blog.csdn.net_zhangphil_article_details_50154707]  
【3】Android谷歌官方Settings开发文档：[http://developer.android.com/guide/topics/ui/settings.html][http_developer.android.com_guide_topics_ui_settings.html]

[Center]: https://image.dandelioncloud.cn/pgy_files/images/2024/01/30/74710edbbcc94280955c4265ac6e5a00.png
[http_blog.csdn.net_zhangphil_article_details_50154513]: http://blog.csdn.net/zhangphil/article/details/50154513
[http_blog.csdn.net_zhangphil_article_details_50154707]: http://blog.csdn.net/zhangphil/article/details/50154707
[http_developer.android.com_guide_topics_ui_settings.html]: http://developer.android.com/guide/topics/ui/settings.html