android-基础编程-Preference

由于SDK封装和提供了一套基于Preference的类，使用Preference通过编辑xml配置文件，只要很少的代码就可以实现了，而且Preference本身已经实现了参数保存，不需要我们再考虑将参数保存文件.类型主要有有两类：一类是管理布局的有PreferenceScreen和PreferenceCategory；另一类是具体的设置元素，有CheckBoxPreference、ListPreference、EditTextPreference和RingtonePreference等.

具体使用：

一。1.生成一个Preference资源文件。

比如：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
  xmlns:android="http://schemas.android.com/apk/res/android">
    <CheckBoxPreference 
        android:defaultValue="true" 
        android:summaryOff="@string/auto_search_disable"
        android:summaryOn="@string/auto_search_enabled"
        android:key="@string/auto_search_enable_key"
        android:title="@string/auto_search_enable_title"
        android:disableDependentsState="false">
    </CheckBoxPreference>
    
    <ListPreference 
        android:dialogTitle="@string/search_rang_key"
        android:entryValues="@array/search_rang_values"
        android:entries="@array/search_rang_strings"
        android:positiveButtonText="@string/enterOk"
        android:negativeButtonText="@string/cancle"
        android:dependency="@string/auto_search_enable_key" 
        android:title="@string/search_rang_key" 
        android:summary="@string/search_rang_summery" 
        android:key="@string/search_rang_key"
        android:defaultValue="@string/search_rang_default_value">
    </ListPreference>
    
</PreferenceScreen>

2.继承之PreferenceActivity代码。

public class ListPreferenceActi extends PreferenceActivity {
    protected void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        
    }
}

3.加载布局。

addPreferencesFromResource(R.xml.listpreference);

效果如下：

二。使用PreferenceCategory

1.布局：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
  xmlns:android="http://schemas.android.com/apk/res/android"   
    android:title="Settings">  
    <PreferenceCategory   
        xmlns:android="http://schemas.android.com/apk/res/android"  
        android:title="Emotions"  
        android:summary="settings about emotions">  
        <CheckBoxPreference    
            android:title="Love me?"   
            android:summaryOn="Yes,I love you!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="true" android:key="@string/category_loveme_key">  
        </CheckBoxPreference> 
         
        <CheckBoxPreference   
            android:title="Hate me?"   
            android:summaryOn="Yes,I hate you!"  
            android:summaryOff="No,you are a good person."  
            android:defaultValue="false">  
        </CheckBoxPreference>       
    </PreferenceCategory>  
    
    <PreferenceCategory   
        xmlns:android="http://schemas.android.com/apk/res/android"  
        android:title="Relations"  
        android:summary="settings about relations">
        <CheckBoxPreference
            android:title="Family?"   
            android:summaryOn="Yes,we are family!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="true">  
        </CheckBoxPreference>  
        
        <CheckBoxPreference   
            android:title="Friends?"   
            android:summaryOn="Yes,we are friends!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="false">  
        </CheckBoxPreference>
    </PreferenceCategory> 
        
</PreferenceScreen>

2.调用：

addPreferencesFromResource(R.xml.preferencescategory);

3.效果：

三。使用PreferenceScreen

1.布局：

<?xml version="1.0" encoding="utf-8"?>
<PreferenceScreen
  xmlns:android="http://schemas.android.com/apk/res/android"   
    android:title="Settings">  
    <PreferenceScreen   
        xmlns:android="http://schemas.android.com/apk/res/android"  
        android:title="Emotions"  
        android:summary="settings about emotions">  
        <CheckBoxPreference    
            android:title="Love me?"   
            android:summaryOn="Yes,I love you!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="true" android:key="@string/screen_loveme_key" android:disableDependentsState="false">  
        </CheckBoxPreference> 
         
        <CheckBoxPreference   
            android:title="Hate me?"   
            android:summaryOn="Yes,I hate you!"  
            android:summaryOff="No,you are a good person."  
            android:defaultValue="false">  
        </CheckBoxPreference>       
    </PreferenceScreen>  
    
    <PreferenceScreen   
        android:title="Relations"  
        android:summary="settings about relations" xmlns:android="http://schemas.android.com/apk/res/android">  
        <CheckBoxPreference   
            android:title="Family?"   
            android:summaryOn="Yes,we are family!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="true">  
        </CheckBoxPreference>  
        <CheckBoxPreference   
            android:title="Friends?"   
            android:summaryOn="Yes,we are friends!"  
            android:summaryOff="No,I am sorry."  
            android:defaultValue="false">  
        </CheckBoxPreference>
    </PreferenceScreen>
    
</PreferenceScreen>

2.调用：

addPreferencesFromResource(R.xml.preferencesscreen);

3.效果：